HP 11i Manuel d'utilisateur

Veritas Volume Manager 5.0 Administrator’s GuideHP-UX 11i v3First EditionManufacturing Part Number: 5992-3942May 2008

11ContentsAdding a RAID-5 log using vxplex ...283Removing a RAID-5 log ...

101Administering disksAdding a disk to VxVMvxdiskadm then proceeds to add the disks.Adding disk device device name to disk group disk group name withd

102 Administering disksRootabilityNote: If you are adding an uninitialized disk, warning and error messages are displayed on the console during the vx

103Administering disksRootabilityVxVM root disk volume restrictionsVolumes on a bootable VxVM root disk have the following configuration restrictions:

104 Administering disksRootabilityBooting root volumesNote: At boot time, the system firmware provides you with a short time period during which you c

105Administering disksRootabilityNote: The -b option to vxcp_lvmroot uses the setboot command to define c0t4d0 as the primary boot device. If this opt

106 Administering disksRootabilityNote: You may want to keep the LVM root disk in case you ever need a boot disk that does not depend on VxVM being pr

107Administering disksRootabilityAdding swap volumes to a VxVM rootable systemTo add a swap volume to an HP-UX system with a VxVM root disk1 Initializ

108 Administering disksDynamic LUN expansionRemoving a persistent dump volumeCaution: The system will not boot correctly if you delete a dump volume w

109Administering disksDynamic LUN expansionAny volumes on the device should only be grown after the device itself has first been grown. Otherwise, sto

110 Administering disksRemoving disksRemoving disksNote: You must disable a disk group as described in “Disabling a disk group” on page 207 before you

12 ContentsAdding a snapshot to a cascaded snapshot hierarchy ...337Refreshing an instant snapshot ...

111Administering disksRemoving disksContinue with operation? [y,n,q,?] (default: y)The vxdiskadm utility removes the disk from the disk group and disp

112 Administering disksRemoving a disk from VxVM controlRemoving a disk with no subdisksTo remove a disk that contains no subdisks from its disk group

113Administering disksRemoving and replacing disksTo replace a disk1 Select menu item 3 (Remove a disk for replacement) from the vxdiskadm main menu.2

114 Administering disksRemoving and replacing disksThe following devices are available as replacements: c0t1d0You can choose one of these disks now, t

115Administering disksRemoving and replacing disksVxVM NOTICE V-5-2-158 Disk replacement completed successfully.9 At the following prompt, indicate wh

116 Administering disksRemoving and replacing disksc0t1d0 c1t1d0You can choose one of these disks to replace mydg02. Choose "none" to initia

117Administering disksEnabling a disk8 After using the vxdiskadm command to replace one or more failed disks in a VxVM cluster, run the following comm

118 Administering disksTaking a disk offlinevxdiskadm enables the specified device.3 At the following prompt, indicate whether you want to enable anot

119Administering disksRenaming a diskRenaming a diskIf you do not specify a VM disk name, VxVM gives the disk a default name when you add the disk to

120 Administering disksDisplaying disk informationThe vxassist command overrides the reservation and creates a 20 megabyte volume on mydg03. However,

13ContentsChapter 12 Administering hot-relocationHow hot-relocation works ...

121Administering disksDisplaying disk informationDisplaying disk information with vxdiskadmDisplaying disk information shows you which disks are initi

122 Administering disksControlling Powerfail TimeoutControlling Powerfail TimeoutPowerfail Timeout is an attribute of a SCSI disk connected to an HP-U

123Administering disksControlling Powerfail TimeoutEnabling or disabling PFTOTo enable or disable PFTO on a disk, use the following command: $ vxdisk

124 Administering disksControlling Powerfail Timeout

Chapter3Administering dynamic multipathing (DMP)The dynamic multipathing (DMP) feature of Veritas Volume Manager (VxVM) provides greater availability,

126 Administering dynamic multipathing (DMP)How DMP worksFor Active/Passive arrays with LUN group failover (A/PG arrays), a group of LUNs that are con

127Administering dynamic multipathing (DMP)How DMP worksFigure 3-1 How DMP represents multiple physical paths to a disk as one nodeAs described in “En

128 Administering dynamic multipathing (DMP)How DMP worksSee “Changing the disk-naming scheme” on page 91 for details of how to change the naming sche

129Administering dynamic multipathing (DMP)How DMP worksDMP is also informed when a connection is repaired or restored, and when you add or remove dev

130 Administering dynamic multipathing (DMP)How DMP worksDMP coexistence with HP-UX native multipathingThe HP-UX 11i v3 release includes support for n

14 ContentsConverting a disk group from shared to private ...424Moving objects between disk groups ...

131Administering dynamic multipathing (DMP)How DMP works3 Restart all the volumes in each disk group:# vxvol -g diskgroup startallThe output from the

132 Administering dynamic multipathing (DMP)How DMP worksand under the new naming scheme as:# vxdisk listDEVICE TYPE DISK GRO

133Administering dynamic multipathing (DMP)Disabling and enabling multipathing for specific devicesEnabling or disabling controllers with shared disk

134 Administering dynamic multipathing (DMP)Disabling and enabling multipathing for specific devices◆Select option 1 to exclude all paths through the

135Administering dynamic multipathing (DMP)Disabling and enabling multipathing for specific devices? Display help about menu?? Display help about the

136 Administering dynamic multipathing (DMP)Enabling and disabling I/O for controllers and storage processorsEnabling and disabling I/O for controller

137Administering dynamic multipathing (DMP)Displaying DMP database informationDisplaying DMP database informationYou can use the vxdmpadm command to l

138 Administering dynamic multipathing (DMP)Displaying the paths to a diskdevicetag: c1t0d3type: simplehostid: zortdisk: name=mydg04 id=9

139Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmAdministering DMP using vxdmpadmThe vxdmpadm utility is a command line admi

140 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmThe physical path is specified by argument to the nodename attribute, whic

15ContentsRunning a rule ...447Identifying configuration prob

141Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmFor A/P arrays in which the I/O policy is set to singleactive, only one pat

142 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmoperations being disabled on that controller by using the vxdmpadm disable

143Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmNAME ENCLR-NAME ARRAY-PORT-ID pWWN=========================================

144 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmGathering and displaying I/O statisticsYou can use the vxdmpadm iostat com

145Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmc2t115d0 87 0 44544 0 0.001200 0.000000c3t115d0 0

146 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmc3t115d0 0 0 0 0 0.000000 0.000000cpu usage =

147Administering dynamic multipathing (DMP)Administering DMP using vxdmpadm primaryDefines a path as being the primary path for an Active/Passive dis

148 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmNote: Starting with release 4.1 of VxVM, I/O policies are recorded in the

149Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmYou can use the size argument to the partitionsize attribute to specify the

150 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadm minimumqThis policy sends I/O on paths that have the minimum number of o

16 ContentsDirty region logging guidelines ... 515Striping guidelines ...

151Administering dynamic multipathing (DMP)Administering DMP using vxdmpadm# vxdmpadm setattr arrayname DISK iopolicy=singleactiveScheduling I/O on th

152 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadm# dd if=/dev/vx/rdsk/mydg/myvol1 of=/dev/null &By running the vxdmpadm

153Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmc4t2d15 1086 0 1086 0 0.390424 0.000000c4t3d15 1048 0 1048 0 0.391221 0.000

154 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmThe disable operation fails if it is issued to a controller that is connec

155Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmFor a system with a volume mirrored across 2 controllers on one HBA, set up

156 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmConfiguring the response to I/O failuresBy default, DMP is configured to r

157Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmThe following example configures time-bound recovery for the enclosure enc0

158 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmThe following example shows how to disable I/O throttling for the paths to

159Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmDisplaying recoveryoption valuesThe following example shows the vxdmpadm ge

160 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmConfiguring DMP path restoration policiesDMP maintains a kernel thread tha

Chapter1Understanding Veritas Volume ManagerVeritasTM Volume Manager (VxVM) by Symantec is a storage management subsystem that allows you to manage ph

161Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmThe interval attribute must be specified for this policy. The default numbe

162 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmDisplaying information about the DMP error-handling threadTo display infor

163Administering dynamic multipathing (DMP)Administering DMP using vxdmpadmNote: By default, DMP uses the most recent APM that is available. Specify t

164 Administering dynamic multipathing (DMP)Administering DMP using vxdmpadm

Chapter4Creating and administering disk groupsThis chapter describes how to create and manage disk groups. Disk groups are named collections of disks

166 Creating and administering disk groupsAs system administrator, you can create additional disk groups to arrange your system’s disks for different

167Creating and administering disk groupsSpecifying a disk group to commandsSpecifying a disk group to commandsNote: Most VxVM commands require superu

168 Creating and administering disk groupsSpecifying a disk group to commandsRules for determining the default disk groupIt is recommended that you us

169Creating and administering disk groupsDisplaying disk group informationIf bootdg is specified as the argument to this command, the default disk gro

170 Creating and administering disk groupsCreating a disk groupflags: online ready private autoconfig autoimport importeddiskid: 963504891.1070.bassd

18 Understanding Veritas Volume Manager Volume snapshots FastResync Hot-relocation Volume setsFurther information on administering Veritas Volume

171Creating and administering disk groupsAdding a disk to a disk groupA disk group must have at least one disk associated with it. A new disk group ca

172 Creating and administering disk groupsRemoving a disk from a disk groupRemoving a disk from a disk groupNote: Before you can remove the last disk

173Creating and administering disk groupsDeporting a disk group There is not enough space on the remaining disks. Plexes or striped subdisks cannot

174 Creating and administering disk groupsImporting a disk groupEnter name of disk group [<group>,list,q,?] (default: list) newdg 5 At the foll

175Creating and administering disk groupsHandling disks with duplicated identifiersEnable access to (import) a disk group Menu: VolumeManager/Disk/Ena

176 Creating and administering disk groupsHandling disks with duplicated identifierscompared with the UDID that is set in the disk’s private region. I

177Creating and administering disk groupsHandling disks with duplicated identifiers# vxdg -o useclonedev=on [-o updateid] import mydgNote: This form o

178 Creating and administering disk groupsHandling disks with duplicated identifiersTo check which disks in a disk group contain copies of this config

179Creating and administering disk groupsHandling disks with duplicated identifiersThese tags can be viewed by using the vxdisk listtag command:# vxdi

180 Creating and administering disk groupsHandling disks with duplicated identifiersTo import the cloned disks, they must be assigned a new disk group

19Understanding Veritas Volume ManagerVxVM and the operating systemVxVM and the operating systemVxVM operates as a subsystem between your operating sy

181Creating and administering disk groupsHandling disks with duplicated identifiersDEVICE TYPE DISK GROUP STATUSEMC0_1 auto:cdsdisk EMC0_1 mydg online

182 Creating and administering disk groupsHandling disks with duplicated identifiersAs the cloned disk EMC0_15 is not tagged as t1, it is not imported

183Creating and administering disk groupsRenaming a disk groupRenaming a disk groupOnly one disk group of a given name can exist per system. It is not

184 Creating and administering disk groupsMoving disks between disk groupsdgid: 774226267.1025.tweetyNote: In this example, the administrator has ch

185Creating and administering disk groupsMoving disk groups between systemsYou can also move a disk by using the vxdiskadm command. Select item 3 (Rem

186 Creating and administering disk groupsMoving disk groups between systemsCaution: The purpose of the lock is to ensure that dual-ported disks (disk

187Creating and administering disk groupsMoving disk groups between systemsThe following error message indicates a recoverable error.VxVM vxdg ERROR V

188 Creating and administering disk groupsMoving disk groups between systemsminor numbers near the top of this range to allow for temporary device num

189Creating and administering disk groupsMoving disk groups between systemsreminor operation on the nodes that are in the cluster to resolve the confl

190 Creating and administering disk groupsHandling conflicting configuration copiesYou can use the following command to discover the maximum number of

20 Understanding Veritas Volume ManagerHow VxVM handles storage managementHow VxVM handles storage managementVxVM uses two types of objects to handle

191Creating and administering disk groupsHandling conflicting configuration copiesFigure 4-1 Typical arrangement of a 2-node campus clusterA serial sp

192 Creating and administering disk groupsHandling conflicting configuration copiesfor the disks in their copies of the configuration database, and al

193Creating and administering disk groupsHandling conflicting configuration copies If the other disks were also imported on another host, no disk can

194 Creating and administering disk groupsHandling conflicting configuration copiesThe following section, “Correcting conflicting configuration inform

195Creating and administering disk groupsReorganizing the contents of disk groupsIn this example, the disk group has four disks, and is split so that

196 Creating and administering disk groupsReorganizing the contents of disk groups To perform online maintenance and upgrading of fault-tolerant syst

197Creating and administering disk groupsReorganizing the contents of disk groupsimported disk group exists with the same name as the target disk grou

198 Creating and administering disk groupsReorganizing the contents of disk groupsFigure 4-6 Disk group join operationThese operations are performed o

199Creating and administering disk groupsReorganizing the contents of disk groupsmust recover the disk group manually as described in the section “Rec

200 Creating and administering disk groupsReorganizing the contents of disk groupswithin storage pools may not be split or moved. See the Veritas Stor

2Legal Notices © Copyright 2008 Hewlett-Packard Development Company, L.P.Publication Date: 2008Confidential computer software. Valid license from HP r

21Understanding Veritas Volume ManagerHow VxVM handles storage managementVxVM writes identification information on physical disks under VxVM control (

201Creating and administering disk groupsReorganizing the contents of disk groupsplexes were placed on the same disks as the data plexes for convenien

202 Creating and administering disk groupsReorganizing the contents of disk groupsFigure 4-7 Examples of disk groups that can and cannot be splitXSnap

203Creating and administering disk groupsReorganizing the contents of disk groupsMoving objects between disk groupsTo move a self-contained set of VxV

204 Creating and administering disk groupsReorganizing the contents of disk groupsFor example, the following output from vxprint shows the contents of

205Creating and administering disk groupsReorganizing the contents of disk groupsDisk group: mydgTY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PU

206 Creating and administering disk groupsReorganizing the contents of disk groupsThe output from vxprint after the split shows the new disk group, my

207Creating and administering disk groupsDisabling a disk groupDisk group: mydgTY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg mydg myd

208 Creating and administering disk groupsDestroying a disk groupDestroying a disk groupThe vxdg command provides a destroy option that removes a disk

209Creating and administering disk groupsUpgrading a disk groupbecomes incompatible with earlier releases of VxVM that do not support the new version.

210 Creating and administering disk groupsUpgrading a disk groupImporting the disk group of a previous version on a Veritas Volume Manager system prev

22 Understanding Veritas Volume ManagerHow VxVM handles storage managementFigure 1-2 How VxVM presents the disks in a disk array as volumes to the ope

211Creating and administering disk groupsUpgrading a disk groupTo list the version of a disk group, use this command:# vxdg list dgnameYou can also de

212 Creating and administering disk groupsManaging the configuration daemon in VxVMTo create a disk group with a previous version, specify the -T vers

213Creating and administering disk groupsBacking up and restoring disk group configuration dataFor more information about how to use vxdctl, refer to

214 Creating and administering disk groupsUsing vxnotify to monitor configuration changes

Chapter5Creating and administering subdisksThis chapter describes how to create and maintain subdisks. Subdisks are the low-level building blocks in a

216 Creating and administering subdisksDisplaying subdisk informationNote: As for all VxVM commands, the default size unit is s, representing a sector

217Creating and administering subdisksMoving subdisksMoving subdisks Moving a subdisk copies the disk space contents of a subdisk onto one or more oth

218 Creating and administering subdisksJoining subdisksFor example, to split subdisk mydg03-02, with size 2000 megabytes into subdisks mydg03-02, mydg

219Creating and administering subdisksAssociating subdisks with plexesSubdisks can also be associated with a plex that already exists. To associate on

220 Creating and administering subdisksAssociating log subdisksIf the volume is enabled, the association operation regenerates data that belongs on th

23Understanding Veritas Volume ManagerHow VxVM handles storage managementDevice Discovery service enables you to add support dynamically for new disk

221Creating and administering subdisksDissociating subdisks from plexesDissociating subdisks from plexesTo break an established connection between a s

222 Creating and administering subdisksChanging subdisk attributes putiln tutiln len commentThe putiln field attributes are maintained on reboot;

Chapter6Creating and administering plexesThis chapter describes how to create and maintain plexes. Plexes are logical groupings of subdisks that creat

224 Creating and administering plexesCreating a striped plexCreating a striped plexTo create a striped plex, you must specify additional attributes. F

225Creating and administering plexesDisplaying plex informationVxVM utilities use plex states to: indicate whether volume contents have been initial

226 Creating and administering plexesDisplaying plex informationEMPTY plex stateVolume creation sets all plexes associated with the volume to the EMPT

227Creating and administering plexesDisplaying plex informationSNAPTMP plex stateThe SNAPTMP plex state is used during a vxassist snapstart operation

228 Creating and administering plexesDisplaying plex informationTEMPRMSD plex stateThe TEMPRMSD plex state is used by vxassist when attaching new data

229Creating and administering plexesAttaching and associating plexesPlex kernel states The plex kernel state indicates the accessibility of the plex t

230 Creating and administering plexesTaking plexes offlineNote: You can also use the command vxassist mirror volume to add a data plex as a mirror to

24 Understanding Veritas Volume ManagerHow VxVM handles storage managementFigure 1-3 Example configuration for disk enclosures connected via a fibre c

231Creating and administering plexesDetaching plexesDetaching plexesTo temporarily detach one data plex in a mirrored volume, use the following comman

232 Creating and administering plexesMoving plexesIf the vxinfo command shows that the volume is unstartable (see “Listing Unstartable Volumes” in the

233Creating and administering plexesCopying volumes to plexesCopying volumes to plexes This task copies the contents of a volume onto a specified plex

234 Creating and administering plexesChanging plex attributesAlternatively, you can first dissociate the plex and subdisks, and then remove them with

Chapter7Creating volumesThis chapter describes how to create volumes in Veritas Volume Manager (VxVM). Volumes are logical devices that appear as phys

236 Creating volumesTypes of volume layoutsTypes of volume layoutsVxVM allows you to create volumes with the following layout types: Concatenated A vo

237Creating volumesTypes of volume layoutsSupported volume logs and mapsVeritas Volume Manager supports the use of several types of logs and maps with

238 Creating volumesCreating a volumeRefer to the following sections for information on creating a volume on which DRL is enabled: “Creating a volume

239Creating volumesUsing vxassist3 Associate plexes with the volume using vxmake vol; see “Creating a volume using vxmake” on page 258.4 Initialize th

240 Creating volumesUsing vxassist Operations result in a set of configuration changes that either succeed or fail as a group, rather than individual

25Understanding Veritas Volume ManagerHow VxVM handles storage managementIn High Availability (HA) configurations, redundant-loop access to storage ca

241Creating volumesUsing vxassistThe section, “Creating a volume on any disk” on page 243 describes the simplest way to create a volume with default a

242 Creating volumesDiscovering the maximum size of a volumemax_nstripe=8min_nstripe=2# for RAID-5, by default create between 3 and 8 stripe columnsm

243Creating volumesCreating a volume on any diskTo discover the value in blocks of the alignment that is set on a disk group, use this command:# vxpri

244 Creating volumesCreating a volume on specific disksCreating a volume on specific disksVxVM automatically selects the disks on which each volume re

245Creating volumesCreating a volume on specific disksSpecifying ordered allocation of storage to volumesOrdered allocation gives you complete control

246 Creating volumesCreating a volume on specific disksFigure 7-2 Example of using ordered allocation to create a striped-mirror volumeAdditionally, y

247Creating volumesCreating a volume on specific disksFigure 7-3 Example of using concatenated disk space to create a mirrored-stripe volumeOther stor

248 Creating volumesCreating a volume on specific disksFigure 7-4 Example of storage allocation used to create a mirrored-stripe volume across control

249Creating volumesCreating a mirrored volumeCreating a mirrored volumeNote: You need a full license to use this feature.A mirrored volume provides da

250 Creating volumesCreating a volume with a version 0 DCO volume# vxassist [-b] [-g diskgroup] make volume length \layout=concat-mirror [nmirror=numb

26 Understanding Veritas Volume ManagerHow VxVM handles storage managementSee “Disk device naming in VxVM” on page 78 and “Changing the disk-naming sc

251Creating volumesCreating a volume with a version 0 DCO volume# vxdg list diskgroupTo upgrade a disk group to version 90, use the following command:

252 Creating volumesCreating a volume with a version 20 DCO volumeCreating a volume with a version 20 DCO volumeTo create a volume with an attached ve

253Creating volumesCreating a striped volumeDirty region logging (DRL), if enabled, speeds recovery of mirrored volumes after a system crash. To enabl

254 Creating volumesCreating a striped volumeYou can specify the disks on which the volumes are to be created by including the disk names on the comma

255Creating volumesMirroring across targets, controllers or enclosuresfor the attribute stripe-mirror-col-split-trigger-pt that is defined in the vxas

256 Creating volumesCreating a RAID-5 volumeSee “Specifying ordered allocation of storage to volumes” on page 245 for a description of other ways in w

257Creating volumesCreating tagged volumesRAID-5 logs can be concatenated or striped plexes, and each RAID-5 log associated with a RAID-5 volume has a

258 Creating volumesCreating a volume using vxmakeTag names and tag values are case-sensitive character strings of up to 256 characters. Tag names can

259Creating volumesCreating a volume using vxmakeIf each column in a RAID-5 plex is to be created from multiple subdisks which may span several physic

260 Creating volumesInitializing and starting a volumeThe following sample description file defines a volume, db, with two plexes, db-01 and db-02: #r

27Understanding Veritas Volume ManagerHow VxVM handles storage management Subdisks (each representing a specific region of a disk) are combined to fo

261Creating volumesInitializing and starting a volumeAs an alternative to the -b option, you can specify the init=active attribute to make a new volum

262 Creating volumesAccessing a volumeAccessing a volumeAs soon as a volume has been created and initialized, it is available for use as a virtual dis

Chapter8Administering volumesThis chapter describes how to perform common maintenance tasks on volumes in Veritas Volume Manager (VxVM). This includes

264 Administering volumesDisplaying volume informationDisplaying volume information You can use the vxprint command to display information about how a

265Administering volumesDisplaying volume information# vxprint -g mydg -t voldefThis is example output from this command:V NAME RVG/VSET/CO KSTATE STA

266 Administering volumesDisplaying volume informationINVALID volume stateThe contents of an instant snapshot volume no longer represent a true point-

267Administering volumesMonitoring and controlling tasksNote: No user intervention is required to set these states; they are maintained internally. On

268 Administering volumesMonitoring and controlling tasksAny tasks started by the utilities invoked by vxrecover also inherit its task ID and task ta

269Administering volumesMonitoring and controlling tasksgenerated when the task completes. When this occurs, the state of the task is printed as EXITE

270 Administering volumesStopping a volumeStopping a volumeStopping a volume renders it unavailable to the user, and changes the volume kernel state f

28 Understanding Veritas Volume ManagerHow VxVM handles storage managementVeritas Volume Manager, such as data change objects (DCOs), and cache object

271Administering volumesStarting a volumeStarting a volumeStarting a volume makes it available for use, and changes the volume state from DISABLED or

272 Administering volumesAdding a mirror to a volumeMirroring all volumes To mirror all volumes in a disk group to available disk space, use the follo

273Administering volumesRemoving a mirrorYou can choose to mirror volumes from disk mydg02 onto anyavailable disk space, or you can choose to mirror o

274 Administering volumesAdding logs and maps to volumesThis command removes the mirror vol01-02 and all associated subdisks. This is equivalent to en

275Administering volumesPreparing a volume for DRL and instant snapshotsPreparing a volume for DRL and instant snapshotsNote: This procedure describes

276 Administering volumesPreparing a volume for DRL and instant snapshotsNote: The vxsnap prepare command automatically enables Persistent FastResync

277Administering volumesPreparing a volume for DRL and instant snapshotsIf required, you can use the vxassist move command to relocate DCO plexes to d

278 Administering volumesPreparing a volume for DRL and instant snapshotsDetermining if DRL is enabled on a volumeTo determine if DRL (configured usin

279Administering volumesUpgrading existing volumes to use version 20 DCOsTo re-enable DRL on a volume, enter this command:# vxvol [-g diskgroup] set d

280 Administering volumesUpgrading existing volumes to use version 20 DCOs# vxdg list diskgroupTo upgrade a disk group to the latest version, use the

29Understanding Veritas Volume ManagerHow VxVM handles storage managementFigure 1-6 VM disk exampleSubdisksA subdisk is a set of contiguous disk block

281Administering volumesAdding traditional DRL logging to a mirrored volumesubsequently create from the snapshot plexes. For example, specify ndcomirs

282 Administering volumesAdding traditional DRL logging to a mirrored volumewhere each bit represents one region in the volume. For example, the size

283Administering volumesAdding a RAID-5 logAdding a RAID-5 logNote: You need a full license to use this feature.Only one RAID-5 plex can exist per RAI

284 Administering volumesResizing a volumeRemoving a RAID-5 log To identify the plex of the RAID-5 log, use the following command: # vxprint [-g diskg

285Administering volumesResizing a volumevxassist command also allows you to specify an increment by which to change the volume’s size.Caution: If you

286 Administering volumesResizing a volume Resizing a volume with a usage type other than FSGEN or RAID5 can result in loss of data. If such an opera

287Administering volumesResizing a volumeNote: If specified, the -b option makes growing the volume a background task.For example, to extend volcat by

288 Administering volumesSetting tags on volumesNote: The vxvol set len command cannot increase the size of a volume unless the needed space is availa

289Administering volumesChanging the read policy for mirrored volumes# vxassist -g mydg settag myvol "dbvol=table space 1"Dotted tag hierarc

290 Administering volumesRemoving a volumeFor example, to set the policy for vol01 to read preferentially from the plex vol01-02, use the following co

30 Understanding Veritas Volume ManagerHow VxVM handles storage managementFigure 1-8 Example of three subdisks assigned to one VM DiskAny VM disk spac

291Administering volumesMoving volumes from a VM diskTo move volumes from a disk1 Select menu item 6 (Move volumes from a disk) from the vxdiskadm mai

292 Administering volumesEnabling FastResync on a volumeEnabling FastResync on a volumeNote: The recommended method for enabling FastResync on a volum

293Administering volumesEnabling FastResync on a volumeNote: To use FastResync with a snapshot, FastResync must be enabled before the snapshot is take

294 Administering volumesPerforming online relayoutPerforming online relayoutNote: You need a full license to use this feature.You can use the vxassis

295Administering volumesPerforming online relayoutPermitted relayout transformationsThe tables below give details of the relayout operations that are

296 Administering volumesPerforming online relayoutTable 8-4 Supported relayout transformations for RAID-5 volumesRelayout to From raid5concatYes.conc

297Administering volumesPerforming online relayoutTable 8-6 Supported relayout transformations for mirrored-stripe volumesRelayout to From mirror-stri

298 Administering volumesPerforming online relayoutSpecifying a non-default layoutYou can specify one or more relayout options to change the default l

299Administering volumesPerforming online relayoutViewing the status of a relayoutOnline relayout operations take some time to perform. You can use th

300 Administering volumesConverting between layered and non-layered volumesinserts a delay of 1000 milliseconds (1 second) between copying each 10-meg

31Understanding Veritas Volume ManagerHow VxVM handles storage managementYou can organize data on subdisks to form a plex by using the following metho

301Administering volumesConverting between layered and non-layered volumesWhen the relayout has completed, use the vxassist convert command to change

302 Administering volumesConverting between layered and non-layered volumes

Chapter9Administering volume snapshotsVeritas Volume Manager (VxVM) provides the capability for taking an image of a volume at a given point in time.

304 Administering volume snapshotsNote: A volume snapshot represents the data that exists in a volume at a given point in time. As such, VxVM does not

305Administering volume snapshotsTraditional third-mirror break-off snapshotsTraditional third-mirror break-off snapshotsThe traditional third-mirror

306 Administering volume snapshotsTraditional third-mirror break-off snapshotsits data plexes. The snapshot volume contains a copy of the original vol

307Administering volume snapshotsFull-sized instant snapshotsFull-sized instant snapshotsFull-sized instant snapshots are a variation on the third-mir

308 Administering volume snapshotsFull-sized instant snapshotsvolume are updated, its original contents are gradually relocated to the snapshot volume

309Administering volume snapshotsSpace-optimized instant snapshotsSpace-optimized instant snapshotsVolume snapshots, such as those described in “Tradi

310 Administering volume snapshotsEmulation of third-mirror break-off snapshotsAs for instant snapshots, space-optimized snapshots use a copy-on-write

32 Understanding Veritas Volume ManagerHow VxVM handles storage managementNote: You can use the Veritas Intelligent Storage Provisioning (ISP) feature

311Administering volume snapshotsLinked break-off snapshot volumes Use the vxsnap make command with the sync=yes and type=full attributes specified t

312 Administering volume snapshotsCascaded snapshotsto recover the mirror volume in the same way as for a DISABLED volume. See “Starting a volume” on

313Administering volume snapshotsCascaded snapshotsto read data from an older snapshot that does not exist in that snapshot, it is obtained by searchi

314 Administering volume snapshotsCascaded snapshotsFigure 9-5 Creating a snapshot of a snapshotEven though the arrangement of the snapshots in this f

315Administering volume snapshotsCascaded snapshotsFigure 9-6 Using a snapshot of a snapshot to restore a databaseIf you have configured snapshots in

316 Administering volume snapshotsCascaded snapshotsFigure 9-7 Dissociating a snapshot volume vxsnap split dissociates a snapshot and its dependent s

317Administering volume snapshotsCreating multiple snapshotsFigure 9-8 Splitting snapshotsCreating multiple snapshotsTo make it easier to create snaps

318 Administering volume snapshotsRestoring the original volume from a snapshotFigure 9-9 Resynchronizing an original volume from a snapshotNote: The

319Administering volume snapshotsCreating instant snapshotsCreating instant snapshotsNote: You need a full license to use this feature.VxVM allows you

320 Administering volume snapshotsCreating instant snapshotsYou can create instant snapshots of volume sets by replacing volume names with volume set

33Understanding Veritas Volume ManagerHow VxVM handles storage managementIn Figure 1-11 a volume, vol06, with two data plexes is mirrored. Each plex o

321Administering volume snapshotsCreating instant snapshotsPreparing to create instant and break-off snapshotsTo prepare a volume for the creation of

322 Administering volume snapshotsCreating instant snapshotscreated, and it must also have the same region size. See “Creating a volume for use as a f

323Administering volume snapshotsCreating instant snapshotsNote: All space-optimized snapshots that share the cache must have a region size that is eq

324 Administering volume snapshotsCreating instant snapshots4 Use the vxassist command to create a volume, snapvol, of the required size and redundanc

325Administering volume snapshotsCreating instant snapshotsFor space-optimized instant snapshots that share a cache object, the specified region size

326 Administering volume snapshotsCreating instant snapshotsFor example, to create the space-optimized instant snapshot, snap4myvol, of the volume, my

327Administering volume snapshotsCreating instant snapshotsCreating and managing full-sized instant snapshotsNote: Full-sized instant snapshots are no

328 Administering volume snapshotsCreating instant snapshotsIf required, you can use the following command to test if the synchronization of a volume

329Administering volume snapshotsCreating instant snapshots Dissociate the snapshot volume entirely from the original volume. This may be useful if y

330 Administering volume snapshotsCreating instant snapshotsIf you specify the -b option to the vxsnap addmir command, you can use the vxsnap snapwait

34 Understanding Veritas Volume ManagerVolume layouts in VxVMVolume layouts in VxVMA VxVM virtual device is defined by a volume. A volume has a layout

331Administering volume snapshotsCreating instant snapshotssynchronization was already in progress on the snapshot, this operation may result in large

332 Administering volume snapshotsCreating instant snapshots[mirdg=snapdg]The optional mirdg attribute can be used to specify the snapshot volume’s cu

333Administering volume snapshotsCreating instant snapshotsNote: This operation is not possible if the linked volume and snapshot are in different dis

334 Administering volume snapshotsCreating instant snapshotsIn this example, snapvol1 is a full-sized snapshot that uses a prepared volume, snapvol2 i

335Administering volume snapshotsCreating instant snapshotsVOLUME INDEX LENGTH KSTATE CONTEXTsvol_0 0 204800 ENABLED -svol_1 1 409600 ENABLED -svol_2

336 Administering volume snapshotsCreating instant snapshotsAdding snapshot mirrors to a volumeIf you are going to create a full-sized break-off snaps

337Administering volume snapshotsCreating instant snapshotsNote: This command is similar in usage to the vxassist snapabort command.If a volume set na

338 Administering volume snapshotsCreating instant snapshotsTo disable resynchronization, specify the syncing=no attribute. This attribute is not supp

339Administering volume snapshotsCreating instant snapshotssnapwait command (but not vxsnap syncwait) to wait for the resynchronization of the reattac

340 Administering volume snapshotsCreating instant snapshotssyncwait) to wait for the resynchronization of the reattached volume to complete, as shown

35Understanding Veritas Volume ManagerVolume layouts in VxVMLayout methodsData in virtual objects is organized to create volumes by using the followin

341Administering volume snapshotsCreating instant snapshotssnapshots remain, snapvol may be dissociated. The snapshot hierarchy is then adopted by sna

342 Administering volume snapshotsCreating instant snapshotsNote: The topmost snapshot volume in the hierarchy must have been fully synchronized for t

343Administering volume snapshotsCreating instant snapshotsAlternatively, you can use the vxsnap list command, which is an alias for the vxsnap -n pri

344 Administering volume snapshotsCreating instant snapshotsSee the vxsnap(1M) manual page for more information about using the vxsnap print and vxsna

345Administering volume snapshotsCreating instant snapshotsinstant snapshot” on page 338 and “Reattaching a linked break-off snapshot volume” on page

346 Administering volume snapshotsCreating instant snapshotsTuning the autogrow attributes of a cacheThe highwatermark, autogrowby and maxautogrow att

347Administering volume snapshotsCreating instant snapshotsCaution: Ensure that the cache is sufficiently large, and that the autogrow attributes are

348 Administering volume snapshotsCreating traditional third-mirror break-off snapshotsCreating traditional third-mirror break-off snapshotsVxVM provi

349Administering volume snapshotsCreating traditional third-mirror break-off snapshotscreating the snapshot mirror is long in contrast to the brief am

350 Administering volume snapshotsCreating traditional third-mirror break-off snapshotsIt is also possible to make a snapshot plex from an existing pl

36 Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-12 Example of concatenationYou can use concatenation with multiple subdisks when

351Administering volume snapshotsCreating traditional third-mirror break-off snapshotsNote: Dissociating or removing the snapshot volume loses the adv

352 Administering volume snapshotsCreating traditional third-mirror break-off snapshotsTo convert an existing plex into a snapshot plex in the SNAPDON

353Administering volume snapshotsCreating traditional third-mirror break-off snapshotsplexes are snapped back. This task resynchronizes the data in th

354 Administering volume snapshotsCreating traditional third-mirror break-off snapshots2 Use the vxassist mirror command to create mirrors of the exis

355Administering volume snapshotsCreating traditional third-mirror break-off snapshotsDisplaying snapshot informationThe vxassist snapprint command di

356 Administering volume snapshotsAdding a version 0 DCO and DCO volumeAdding a version 0 DCO and DCO volumeNote: The procedure described in this sect

357Administering volume snapshotsAdding a version 0 DCO and DCO volume3 Use the following command to add a DCO and DCO volume to the existing volume:#

358 Administering volume snapshotsAdding a version 0 DCO and DCO volumethe volume named vol1 (the TUTIL0 and PUTIL0 columns are omitted for clarity):T

359Administering volume snapshotsAdding a version 0 DCO and DCO volumeThis form of the command dissociates the DCO object from the volume but does not

360 Administering volume snapshotsAdding a version 0 DCO and DCO volume

37Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-13 Example of spanningCaution: Spanning a plex across multiple disks increases th

Chapter10Creating and administering volume setsThis chapter describes how to use the vxvset command to create and administer volume sets in Veritas Vo

362 Creating and administering volume setsCreating a volume set Volume sets can be used in place of volumes with the following vxsnap operations on i

363Creating and administering volume setsListing details of volume setsCaution: The -f (force) option must be specified if the volume being added, or

364 Creating and administering volume setsRemoving a volume from a volume set# vxvset -g mydg list set1VOLUME INDEX LENGTH KSTATE

365Creating and administering volume setsRaw device node access to component volumesCaution: Writing directly to or reading from the raw device node o

366 Creating and administering volume setsRaw device node access to component volumesvalue of the makedev attribute is currently set to on. The access

367Creating and administering volume setsRaw device node access to component volumesThe syntax for setting the compvol_access attribute on a volume se

368 Creating and administering volume setsRaw device node access to component volumes

Chapter11Configuring off-host processingOff-host processing allows you to implement the following activities:Data backup As the requirement for 24 x 7

370 Configuring off-host processingImplementing off-host processing solutionsOff-host processing is made simpler by using linked break-off snapshots,

38 Understanding Veritas Volume ManagerVolume layouts in VxVMStriping (RAID-0)Note: You need a full license to use this feature.Striping (RAID-0) is u

371Configuring off-host processingImplementing off-host processing solutions Implementing decision supportThese applications use the Persistent FastR

372 Configuring off-host processingImplementing off-host processing solutionsNote: If the volume was created under VxVM 4.0 or a later release, and it

373Configuring off-host processingImplementing off-host processing solutionsIf a database spans more than one volume, you can specify all the volumes

374 Configuring off-host processingImplementing off-host processing solutions# vxsnap -g snapvoldg reattach snapvol source=vol \sourcedg=volumedgFor e

375Configuring off-host processingImplementing off-host processing solutionsThis command returns on if FastResync is enabled; otherwise, it returns of

376 Configuring off-host processingImplementing off-host processing solutions8 On the primary host, if you temporarily suspended updates to a volume i

377Configuring off-host processingImplementing off-host processing solutionsFor example, to reattach the snapshot volumes svol1, svol2 and svol3:# vxs

378 Configuring off-host processingImplementing off-host processing solutions

Chapter12Administering hot-relocationIf a volume has a disk I/O failure (for example, the disk has an uncorrectable error), Veritas Volume Manager (Vx

380 Administering hot-relocationHow hot-relocation worksHow hot-relocation worksHot-relocation allows a system to react automatically to I/O failures

39Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-14 Striping across three columnsA stripe consists of the set of stripe units at t

381Administering hot-relocationHow hot-relocation worksspares (marked spare) in the disk group where the failure occurred. It then relocates the subdi

382 Administering hot-relocationHow hot-relocation worksFigure 12-1 Example of hot-relocation for a subdisk in a RAID-5 volumemydg01 mydg02 mydg03 myd

383Administering hot-relocationHow hot-relocation worksPartial disk failure mail messagesIf hot-relocation is enabled when a plex or disk is detached

384 Administering hot-relocationHow hot-relocation worksComplete disk failure mail messagesIf a disk fails completely and hot-relocation is enabled, t

385Administering hot-relocationConfiguring a system for hot-relocationdoes not take place. If relocation is not possible, the system administrator is

386 Administering hot-relocationDisplaying spare disk informationAfter a successful relocation, remove and replace the failed disk as described in “Re

387Administering hot-relocationMarking a disk as a hot-relocation spareMarking a disk as a hot-relocation spareHot-relocation allows the system to rea

388 Administering hot-relocationRemoving a disk from use as a hot-relocation spareelectronic mail. After successful relocation, you may want to replac

389Administering hot-relocationMaking a disk available for hot-relocation useTo use vxdiskadm to exclude a disk from hot-relocation use1 Select menu i

390 Administering hot-relocationConfiguring hot-relocation to use only spare disksEnter disk name [<disk>,list,q,?] mydg01The following confirma

40 Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-15 shows a striped plex with three equal sized, single-subdisk columns. There is

391Administering hot-relocationMoving and unrelocating subdisksVolume home Subdisk mydg02-03 relocated to mydg05-01,but not yet recovered.Before you m

392 Administering hot-relocationMoving and unrelocating subdiskssubdisks using vxassist” on page 392 and “Moving and unrelocating subdisks using vxunr

393Administering hot-relocationMoving and unrelocating subdiskswithout using the original offsets. Refer to the vxunreloc(1M) manual page for more inf

394 Administering hot-relocationMoving and unrelocating subdisksExamining which subdisks were hot-relocated from a diskIf a subdisk was hot relocated

395Administering hot-relocationModifying the behavior of hot-relocationIf the system goes down after the new subdisks are created on the destination d

396 Administering hot-relocationModifying the behavior of hot-relocationAlternatively, you can use the following command:# nohup /etc/vx/bin/vxrelocd

Chapter13Administering cluster functionalityA cluster consists of a number of hosts or nodes that share a set of disks. The main benefits of cluster c

398 Administering cluster functionalityOverview of cluster volume managementenabled, all the nodes in the cluster can share VxVM objects such as share

399Administering cluster functionalityOverview of cluster volume managementmembership. Each node starts up independently and has its own cluster monit

400 Administering cluster functionalityOverview of cluster volume managementFigure 13-1 Example of a 4-node cluster To the cluster monitor, all nodes

ContentsChapter 1 Understanding Veritas Volume ManagerVxVM and the operating system ...

41Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-16 Example of a striped plex with concatenated subdisks per columnSee “Creating a

401Administering cluster functionalityOverview of cluster volume managementPrivate and shared disk groupsTwo types of disk groups are defined:In a clu

402 Administering cluster functionalityOverview of cluster volume managementcluster-shareable disk group is available as long as at least one node is

403Administering cluster functionalityOverview of cluster volume managementThe following table summarizes the allowed and conflicting activation modes

404 Administering cluster functionalityOverview of cluster volume managementNote: The activation mode of a disk group controls volume I/O from differe

405Administering cluster functionalityOverview of cluster volume managementpolicy. However, in some cases, it is not desirable to have all nodes react

406 Administering cluster functionalityOverview of cluster volume managementLocal detach policyCaution: Do not use the local detach policy if you use

407Administering cluster functionalityOverview of cluster volume managementDisk group failure policyThe local detach policy by itself is insufficient

408 Administering cluster functionalityOverview of cluster volume managementGuidelines for choosing detach and failure policiesIn most cases it is rec

409Administering cluster functionalityOverview of cluster volume managementThe default settings for the detach and failure policies are global and dgd

410 Administering cluster functionalityCluster initialization and configurationCluster initialization and configurationBefore any nodes can join a new

42 Understanding Veritas Volume ManagerVolume layouts in VxVMMirroring (RAID-1)Note: You need a full license to use this feature with disks other than

411Administering cluster functionalityCluster initialization and configurationDuring cluster reconfiguration, VxVM suspends I/O to shared disks. I/O r

412 Administering cluster functionalityCluster initialization and configurationTable 13-5 Node abort messagesReason Descriptioncannot find disk on sla

413Administering cluster functionalityCluster initialization and configurationSee the vxclustadm(1M) manual page for more information about vxclustadm

414 Administering cluster functionalityCluster initialization and configurationWhen an error occurs, such as when a check on a slave fails or a node l

415Administering cluster functionalityCluster initialization and configurationstopped, volume reconfiguration cannot take place. Other nodes can join

416 Administering cluster functionalityCluster initialization and configurationNote: The -r reset option to vxconfigd restarts the vxconfigd daemon an

417Administering cluster functionalityMultiple host failover configurationsNote: Once shutdown succeeds, the node has left the cluster. It is not poss

418 Administering cluster functionalityMultiple host failover configurationscorrupted. Similar corruption can also occur if a file system or database

419Administering cluster functionalityMultiple host failover configurationsFor details on how to clear locks and force an import, see “Moving disk gro

420 Administering cluster functionalityAdministering VxVM in cluster environmentsAdministering VxVM in cluster environmentsThe following sections desc

43Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-17 Mirrored-stripe volume laid out on six disksSee “Creating a mirrored-stripe vo

421Administering cluster functionalityAdministering VxVM in cluster environmentsDetermining if a disk is shareableThe vxdisk utility manages VxVM disk

422 Administering cluster functionalityAdministering VxVM in cluster environmentsThe following is example output for the command vxdg list group1 on t

423Administering cluster functionalityAdministering VxVM in cluster environmentsCaution: The operating system cannot tell if a disk is shared. To prot

424 Administering cluster functionalityAdministering VxVM in cluster environments Some of the nodes to which disks in the disk group are attached are

425Administering cluster functionalityAdministering VxVM in cluster environmentscan join two private disk groups on any cluster node where those disk

426 Administering cluster functionalityAdministering VxVM in cluster environmentsSetting the disk group failure policy on a shared disk groupNote: The

427Administering cluster functionalityAdministering VxVM in cluster environmentsMultiple opens by the same node are also supported. Any attempts by ot

428 Administering cluster functionalityAdministering VxVM in cluster environmentsUpgrading the cluster protocol versionNote: The cluster protocol vers

429Administering cluster functionalityAdministering VxVM in cluster environmentsThis command produces output similar to the following: OPERATIONS BLOC

430 Administering cluster functionalityAdministering VxVM in cluster environments

44 Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-18 Striped-mirror volume laid out on six disksSee “Creating a striped-mirror vol

Chapter14Administeringsites and remote mirrorsIn a Remote Mirror configuration (also known as a campus cluster or stretch cluster) the hosts and stora

432 Administering sites and remote mirrorsIf a disk group is configured across the storage at the sites, and inter-site communication is disrupted, th

433Administering sites and remote mirrorsTo enhance read performance, VxVM will service reads from the plexes at the local site where an application i

434 Administering sites and remote mirrorsConfiguring sites for hosts and disksConfiguring sites for hosts and disksNote: The Remote Mirror feature re

435Administering sites and remote mirrorsConfiguring site consistency on a disk groupThe -f option allows the requirement to be removed if the site is

436 Administering sites and remote mirrorsSetting the siteread policy on a volumeTo turn on the site consistency requirement for an existing volume, u

437Administering sites and remote mirrorsSite-based allocation of storage to volumesNote: If the Site Awareness license is installed on all the hosts

438 Administering sites and remote mirrorsSite-based allocation of storage to volumesExamples of storage allocation using sitesThe examples in the fol

439Administering sites and remote mirrorsMaking an existing disk group site consistentMaking an existing disk group site consistentTo make an existing

440 Administering sites and remote mirrorsFire drill — testing the configurationFire drill — testing the configurationCaution: To avoid potential loss

45Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-19 How the failure of a single disk affects mirrored-stripe and striped-mirror vo

441Administering sites and remote mirrorsFailure scenarios and recovery proceduressite state to ACTIVE, and initiates recovery of the plexes. When all

442 Administering sites and remote mirrorsFailure scenarios and recovery proceduresRecovery from a loss of site connectivityIf the network links betwe

443Administering sites and remote mirrorsFailure scenarios and recovery proceduresat the other sites. When the storage comes back online, you can use

444 Administering sites and remote mirrorsFailure scenarios and recovery procedures

Chapter15Using Storage ExpertAbout Storage ExpertSystem administrators often find that gathering and interpreting data about large and complex configu

446 Using Storage ExpertHow Storage Expert worksHow Storage Expert worksStorage Expert components include a set of rule scripts and a rules engine. Th

447Using Storage ExpertRunning Storage ExpertSee “Rule definitions and attributes” on page 456.Discovering what a rule doesTo obtain details about wha

448 Using Storage ExpertRunning Storage Expert# vxse_dg1 -g mydg run VxVM vxse:vxse_dg1 INFO V-5-1-5511 vxse_vxdg1 - RESULTS -------------------------

449Using Storage ExpertIdentifying configuration problems using Storage Expert A value specified on the command line. A value specified in a user-d

450 Using Storage ExpertIdentifying configuration problems using Storage ExpertChecking for large mirror volumes without a dirty region log (vxse_drl1

46 Understanding Veritas Volume ManagerVolume layouts in VxVMAlthough both mirroring (RAID-1) and RAID-5 provide redundancy of data, they use differen

451Using Storage ExpertIdentifying configuration problems using Storage ExpertA mirror of the RAID-5 log protects against loss of data due to the fail

452 Using Storage ExpertIdentifying configuration problems using Storage ExpertChecking the number of configuration copies in a disk group (vxse_dg5)T

453Using Storage ExpertIdentifying configuration problems using Storage Expert volumes needing recoverySee “Reattaching plexes” on page 231.See “Star

454 Using Storage ExpertIdentifying configuration problems using Storage ExpertChecking the number of columns in striped volumes (vxse_stripes2)The de

455Using Storage ExpertIdentifying configuration problems using Storage ExpertChecking the system name (vxse_host)Rule vxse_host can be used to confir

456 Using Storage ExpertRule definitions and attributesRule definitions and attributesYou can use the info keyword to show a description of a rule.See

457Using Storage ExpertRule definitions and attributesYou can use the list and check keywords to show what attributes are available for a rule and to

458 Using Storage ExpertRule definitions and attributesTable 15-2 Rule attributes and default attribute valuesRule Attribute Default valueDescriptionv

459Using Storage ExpertRule definitions and attributesvxse_mirstripe large_mirror_sizensd_threshold1g (1GB)8Large mirror-stripe threshold size.Warn if

460 Using Storage ExpertRule definitions and attributesvxse_redundancy volume_redundancy 0Volume redundancy check. The value of 2 performs a mirror re

47Understanding Veritas Volume ManagerVolume layouts in VxVMparity stripe. Figure 1-21 shows the row and column arrangement of a traditional RAID-5 ar

461Using Storage ExpertRule definitions and attributesvxse_volplex - - No user-configurable variables.Table 15-2 Rule attributes and default attribute

462 Using Storage ExpertRule definitions and attributes

Chapter16Performance monitoring and tuningVeritas Volume Manager (VxVM) can improve overall system performance by optimizing the layout of data storag

464 Performance monitoring and tuningPerformance guidelinesStripingStriping improves access performance by cutting data into slices and storing it on

465Performance monitoring and tuningPerformance guidelinesCombining mirroring and stripingNote: You need a full license to use this feature.Mirroring

466 Performance monitoring and tuningPerformance guidelinesVolume read policiesTo help optimize performance for different types of volumes, VxVM suppo

467Performance monitoring and tuningPerformance monitoringNote: To improve performance for read-intensive workloads, you can attach up to 32 data plex

468 Performance monitoring and tuningPerformance monitoringTracing volume operationsUse the vxtrace command to trace operations on specified volumes,

469Performance monitoring and tuningPerformance monitoringan operation makes it possible to measure the impact of that particular operation. The follo

470 Performance monitoring and tuningPerformance monitoringSuch output helps to identify volumes with an unusually large number of operations or exces

48 Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-22 Veritas Volume Manager RAID-5 arrayNote: Mirroring of RAID-5 volumes is not s

471Performance monitoring and tuningPerformance monitoringIf two volumes (other than the root volume) on the same disk are busy, move them so that eac

472 Performance monitoring and tuningTuning VxVMwrites where mirroring can improve performance depends greatly on the disks, the disk controller, whet

473Performance monitoring and tuningTuning VxVMTuning guidelines for large systemsOn smaller systems (with fewer than a hundred disk drives), tuning i

474 Performance monitoring and tuningTuning VxVMTo set the number of configuration copies for a new disk group, use the nconfig operand with the vxdg

475Performance monitoring and tuningTuning VxVMTunable parametersThe following sections describe specific tunable parameters.dmp_cache_openIf set to o

476 Performance monitoring and tuningTuning VxVMThe value of this tunable is changed by using the vxdmpadm settune command.dmp_health_timeDMP detects

477Performance monitoring and tuningTuning VxVMincreasing the value of this tunable. For example, for the HDS 9960 A/A array, the optimal value is bet

478 Performance monitoring and tuningTuning VxVMdmp_restore_policyThe DMP restore policy, which can be set to 0 (CHECK_ALL), 1 (CHECK_DISABLED), 2 (CH

479Performance monitoring and tuningTuning VxVMdmp_stat_intervalThe time interval between gathering DMP statistics. The default and minimum value is 1

480 Performance monitoring and tuningTuning VxVMSince the region size must be the same on all nodes in a cluster for a shared volume, the value of the

49Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-23 Left-symmetric layoutFor each stripe, data is organized starting to the right

481Performance monitoring and tuningTuning VxVMperforming operations of a certain size and can fail unexpectedly if they issue oversized ioctl request

482 Performance monitoring and tuningTuning VxVMvolcvm_smartsyncIf set to 0, volcvm_smartsync disables SmartSync on shared disk groups. If set to 1, t

483Performance monitoring and tuningTuning VxVMvoliomem_maxpool_szThe maximum memory requested from the system by VxVM for internal purposes. This tun

484 Performance monitoring and tuningTuning VxVMtracing event records. As trace buffers are requested to be stored in the kernel, the memory for them

485Performance monitoring and tuningTuning VxVMNote: The memory allocated for this cache is exclusively dedicated to it. It is not available for other

486 Performance monitoring and tuningTuning VxVM

AppendixACommands summaryThis appendix summarizes the usage and purpose of important commonly-used commands in Veritas Volume Manager (VxVM). Referenc

488 Commands summaryother commands and scripts, and which are not intended for general use, are not located in /opt/VRTS/bin and do not have manual pa

489Commands summaryvxinfo [-g diskgroup] [volume ...] Displays information about the accessibility and usability of volumes. See “Listing Unstartable

490 Commands summaryvxdiskadd [devicename ...] Adds a disk specified by device name. See “Using vxdiskadd to place a disk under control of VxVM” on pa

50 Understanding Veritas Volume ManagerVolume layouts in VxVMNote: Failure of more than one column in a RAID-5 plex detaches the volume. The volume is

491Commands summaryvxedit [-g diskgroup] set \ spare=on|off disknameAdds/removes a disk from the pool of hot-relocation spares.See “Marking a disk as

492 Commands summaryTable A-3 Creating and administering disk groupsCommand Descriptionvxdg [-s] init diskgroup \ [diskname=]devicenameCreates a disk

493Commands summaryvxdg [-o expand] listmove sourcedg \ targetdg object ...Lists the objects potentially affected by moving a disk group.See “Listing

494 Commands summaryvxrecover -g diskgroup -sb Starts all volumes in an imported disk group.See “Moving disk groups between systems” on page 185.Examp

495Commands summaryvxsd [-g diskgroup] assoc plex \ subdisk1:0 ... subdiskM:N-1Adds subdisks to the ends of the columns in a striped or RAID-5 volume.

496 Commands summaryvxunreloc [-g diskgroup] original_disk Relocates subdisks to their original disks.See “Moving and unrelocating subdisks using vxun

497Commands summaryvxmake [-g diskgroup] plex plex \ layout=stripe|raid5 stwidth=W \ ncolumn=N sd=subdisk1[,subdisk2,...]Creates a striped or RAID-5 p

498 Commands summaryvxplex [-g diskgroup] cp volume newplex Copies a volume onto a plex.See “Copying volumes to plexes” on page 233.Example:# vxplex -

499Commands summaryvxassist -b [-g diskgroup] make \ volume length [layout=layout ] [attributes]Creates a volume.See “Creating a volume on any disk” o

500 Commands summaryvxassist -b [-g diskgroup] make \ volume length layout=mirror \ mirror=ctlr [attributes]Creates a volume with mirrored data plexes

6 ContentsDCO volume versioning ... 68FastResync limitations ...

51Understanding Veritas Volume ManagerVolume layouts in VxVMLogs are associated with a RAID-5 volume by being attached as log plexes. More than one lo

501Commands summaryTable A-7 Administering volumesCommand Descriptionvxassist [-g diskgroup] mirror volume \ [attributes]Adds a mirror to a volume.See

502 Commands summaryvxsnap [-g diskgroup] prepare volume \[drl=on|sequential|off]Prepares a volume for instant snapshots and for DRL logging. See “Pre

503Commands summaryvxmake [-g diskgroup] cache \cache_object cachevolname=volume \[regionsize=size]Creates a cache object for use by space-optimized i

504 Commands summaryvxsnap [-g diskgroup] unprepare volume Removes support for instant snapshots and DRL logging from a volume.See “Removing support f

505Commands summaryvxassist [-g diskgroup] convert \volume [layout=layout] [convert_options]Converts between a layered volume and a non-layered volume

506 Commands summaryvxtask pause task Suspends operation of a task.See “Using the vxtask command” on page 269.Example:# vxtask pause mytaskvxtask -p [

507Commands summaryOnline manual pagesOnline manual pagesManual pages are organized into three sections: Section 1M — administrative commands Sectio

508 Commands summaryOnline manual pagesvxconfigd Veritas Volume Manager configuration daemonvxconfigrestore Restore disk group configuration.vxcp_lvmr

509Commands summaryOnline manual pagesvxmend Mend simple problems in configuration records.vxmirror Mirror volumes on a disk or control default mirror

510 Commands summaryOnline manual pagesSection 4 — file formatsManual pages in section 4 describe the format of files that are used by Veritas Volume

52 Understanding Veritas Volume ManagerVolume layouts in VxVMFigure 1-25 Example of a striped-mirror layered volumeFigure 1-25 illustrates the structu

AppendixBConfiguring Veritas Volume ManagerThis appendix provides guidelines for setting up efficient storage management after installing the Veritas

512 Configuring Veritas Volume ManagerAdding unsupported disk arrays as JBODsOptional Setup Tasks Place the root disk under VxVM control and mirror i

513Configuring Veritas Volume ManagerGuidelines for configuring storagegroups. Storage pools are only required if you intend using the ISP feature of

514 Configuring Veritas Volume ManagerGuidelines for configuring storage Leave the Veritas Volume Manager hot-relocation feature enabled. See “Hot-re

515Configuring Veritas Volume ManagerGuidelines for configuring storageDirty region logging guidelinesDirty region logging (DRL) can speed up recovery

516 Configuring Veritas Volume ManagerGuidelines for configuring storage If more than one plex of a mirrored volume is striped, configure the same st

517Configuring Veritas Volume ManagerGuidelines for configuring storageThe hot-relocation feature is enabled by default. The associated daemon, vxrelo

518 Configuring Veritas Volume ManagerControlling VxVM’s view of multipathed devicessubdisks to determine whether they should be relocated to more sui

519Configuring Veritas Volume ManagerConfiguring cluster supportConfiguring shared disk groupsThis section describes how to configure shared disks in

520 Configuring Veritas Volume ManagerReconfiguration tasksIf dirty region logs exist, ensure they are active. If not, replace them with larger ones.T

53Understanding Veritas Volume ManagerVolume layouts in VxVMplex (for example, resizing the volume, changing the column width, or adding a column). Sy

GlossaryActive/Active disk arraysThis type of multipathed disk array allows you to access a disk in the disk array through all the paths to the disk s

522 GlossaryclusterA set of hosts (each termed a node) that share a set of disks.cluster managerAn externally-provided daemon that runs on each node i

523Glossarymaintained in the DCO volume. Otherwise, the DRL is allocated to an associated subdisk called a log subdisk.disabled pathA path to a disk t

524 GlossaryAn alternative term for a disk name.disk media record A configuration record that identifies a particular disk, by disk ID, and gives that

525GlossaryAn area of a disk under VxVM control that is not allocated to any subdisk or reserved for use by any other VxVM object.free subdiskA subdis

526 GlossaryWhere there are multiple physical access paths to a disk connected to a system, the disk is called multipathed. Any software residing on t

527GlossaryA form of FastResync that can preserve its maps across reboots of the system by storing its change map in a DCO volume on disk. Also see da

528 GlossaryThe disk containing the root file system. This disk may be under VxVM control.root file system The initial file system mounted as part of

529GlossaryA plex that is not as long as the volume or that has holes (regions of the plex that do not have a backing subdisk).Storage Area Network (S

530 GlossaryA virtual disk, representing an addressable range of disk blocks used by applications such as file systems or databases. A volume is a col

54 Understanding Veritas Volume ManagerOnline relayoutOnline relayoutNote: You need a full license to use this feature.Online relayout allows you to c

IndexSymbols/dev/vx/dmp directory 126/dev/vx/rdmp directory 126/etc/default/vxassist file 241, 390/etc/default/vxdg defaults file 403/etc/default/vxdg

532 Indexndcomirror 251, 252, 357ndcomirs 275, 321newvol 330nmirror 330nomanual 146nopreferred 146plex 234preferred priority 146primary 147putil 222,

533Indexclustersactivating disk groups 403activating shared disk groups 425activation modes for shared disk groups 402benefits 397checking cluster pro

534 Indexcrash dumpsusing VxVM volumes for 107Cross-platform Data Sharing (CDS)alignment constraints 242disk format 81CVMcluster functionality of VxVM

535IndexA/P-C 126A/PF 126A/PF-C 126A/PG 126A/PG-C 126Active/Active 126Active/Passive 125adding disks to DISKS category 87adding vendor-supplied suppor

536 Indexserial split brain condition 190setting connectivity policies in clusters 425setting default disk group 168setting failure policies in cluste

537Indexspares 388removing from VxVM control 112, 172removing tags from 178removing with subdisks 111, 112renaming 119replacing 112replacing removed 1

538 Indexdmp_scsi_timeout tunable 478dmp_stat_interval tunable 479DRLadding log subdisks 220adding logs to mirrored volumes 281checking existence of 4

539Indexuse with snapshots 66fastresync attribute 251, 252, 293file systemsgrowing using vxresize 285shrinking using vxresize 285unmounting 290fire dr

540 Indexinitialization of disks 90instant snapshotsbacking up multiple volumes 333cascaded 312creating backups 319creating for volume sets 334creatin

55Understanding Veritas Volume ManagerOnline relayoutamount of temporary space that is required is usually 10% of the size of the volume, from a minim

541IndexLUN group failover 126LUN groupsdisplaying details of 140LUNsidle 477Mmapsadding to volumes 274usage with volumes 237master nodedefined 400dis

542 Indexplex attribute 234renaming disks 119subdisk 29subdisk attribute 221VM disk 29volume 31naming schemechanging for disks 91changing for TPD encl

543Indexhot spots identified by I/O traces 472impact of number of disk group configuration copies 473improving for instant snapshot synchronization 34

544 Indexcondition flags 228converting to snapshot 351copying 233creating 223creating striped 224defined 30detaching from volumes temporarily 231disco

545Indexperformance of 466prefer 289round 289select 289siteread 289, 433, 434, 436split 289read-only mode 402readonly mode 402RECOVER plex condition 2

546 Indexread policy 289rulesattributes 458checking attribute values 447checking disk group configuration copies 451checking disk group version number

547Indexsiteconsistent attribute 435siteread read policy 289, 433, 434, 436sitesreattaching 440size units 216slave nodesdefined 400SmartSync 62disabli

548 Indexstandby path attribute 147statesfor plexes 224of link objects 311volume 265statistics gathering 128storageordered allocation of 245, 251, 257

549Indexphysical disk placement 513putil attribute 222RAID-5 failure of 380RAID-5 plex, configuring 516removing from VxVM 221restrictions on moving 21

550 Indexvol_default_iodelay 479vol_fmr_logsz 68, 479vol_max_vol 480vol_maxio 480vol_maxioctl 480vol_maxparallelio 481vol_maxspecialio 481vol_subdisk_

56 Understanding Veritas Volume ManagerOnline relayout(shown by the shaded area) decreases the overall storage space that the volume requires.Figure 1

551IndexDETACHED 267DISABLED 267ENABLED 267volume length, RAID-5 guidelines 516volume resynchronization 59volume setsadding volumes to 362administerin

552 Indexeffect of growing on FastResync maps 73enabling FastResync on 292enabling FastResync on new 251excluding storage from use by vxassist 244find

553Indexzeroing out contents of 261vxassistadding a log subdisk 220adding a RAID-5 log 283adding DCOs to volumes 357adding DRL logs 281adding mirrors

554 Indexreattaching version 0 DCOs to volumes 359removing version 0 DCOs from volumes 358vxdctlchecking cluster protocol version 427managing vxconfig

555Indexvxdisk scandisksrescanning devices 82scanning devices 82vxdiskaddadding disks to disk groups 171creating disk groups 171placing disks under Vx

556 Indexremoving instant snapshots 341removing plexes 234removing snapshots from a cache 347removing subdisks from VxVM 221removing volumes 290renami

557Indexvxse_dg2rule to check disk group configuration copies 451vxse_dg3rule to check on disk config size 451vxse_dg4rule to check disk group version

558 Indexmoving subdisks after hot-relocation 392restarting after errors 394specifying different offsets for unrelocated subdisks 393unrelocating subd

57Understanding Veritas Volume ManagerOnline relayoutFigure 1-30 Example of increasing the stripe width for the columns in a volumeFor details of how

58 Understanding Veritas Volume ManagerOnline relayout The number of mirrors in a mirrored volume cannot be changed using relayout. Only one relayou

59Understanding Veritas Volume ManagerVolume resynchronizationVolume resynchronizationWhen storing data redundantly and using mirrored or RAID-5 volum

60 Understanding Veritas Volume ManagerDirty region loggingResynchronization of data in the volume is done in the background. This allows the volume t

7ContentsTaking a disk offline ...118Renaming a disk ...

61Understanding Veritas Volume ManagerDirty region loggingbecomes the least recently accessed for writes. This allows writes to the same region to be

62 Understanding Veritas Volume ManagerDirty region loggingSmartSync recovery acceleratorThe SmartSync feature of Veritas Volume Manager increases the

63Understanding Veritas Volume ManagerVolume snapshotsRedo log volume configurationA redo log is a log of changes to the database data. Because the da

64 Understanding Veritas Volume ManagerVolume snapshotsFigure 1-31 Volume snapshot as a point-in-time image of a volumeThe traditional type of volume

65Understanding Veritas Volume ManagerVolume snapshotsmirror snapshots such as immediate availability and easier configuration and administration. You

66 Understanding Veritas Volume ManagerFastResyncFastResyncNote: You need a Veritas FlashSnap or FastResync license to use this feature.The FastResync

67Understanding Veritas Volume ManagerFastResyncsnapshot is taken, it can be accessed independently of the volume from which it was taken. In a cluste

68 Understanding Veritas Volume ManagerFastResyncAvailability (HA) environment requires the full resynchronization of a mirror when it is reattached t

69Understanding Veritas Volume ManagerFastResyncVersion 0 DCO volume layoutIn VxVM releases 3.2 and 3.5, the DCO object only managed information about

70 Understanding Veritas Volume ManagerFastResync(by default) are used either for tracking writes to snapshots, or as copymaps. The size of the DCO vo

8 ContentsDisplaying the status of the DMP path restoration thread ...161Displaying information about the DMP error-handling thread ...

71Understanding Veritas Volume ManagerFastResyncFigure 1-32 Mirrored volume with persistent FastResync enabledTo create a traditional third-mirror sna

72 Understanding Veritas Volume ManagerFastResyncNote: Space-optimized instant snapshots do not require additional full-sized plexes to be created. In

73Understanding Veritas Volume ManagerFastResyncNote: The vxsnap reattach, dis and split operations are not supported for instant space-optimized snap

74 Understanding Veritas Volume ManagerFastResyncdifferent effects on the map that FastResync uses to track changes to the original volume: For a ver

75Understanding Veritas Volume ManagerHot-relocationassociation. However, in such a case, you can use the vxplex snapback command with the -f (force)

76 Understanding Veritas Volume ManagerVolume setsand availability characteristics of the underlying volumes. For example, file system metadata could

Chapter2Administering disksThis chapter describes the operations for managing disks used by the Veritas Volume Manager (VxVM). This includes placing d

78 Administering disksDisk devicesand /dev/rdisk directories. To maintain backward compatibility, HP-UX also creates legacy devices in the /dev/dsk an

79Administering disksDisk devicesThe syntax of a legacy device name is c#t#d#, where c# represents a controller on a host bus adapter, t# is the targe

80 Administering disksDisk devicesPrivate and public disk regionsMost VM disks have two regions:private region A small area where configuration inform

9ContentsCreating subdisks ...215Displaying subdisk inform

81Administering disksDisk devicesauto When the vxconfigd daemon is started, VxVM obtains a list of known disk device addresses from the operating syst

82 Administering disksDiscovering and configuring newly added disk devicesDiscovering and configuring newly added disk devicesWhen you physically conn

83Administering disksDiscovering and configuring newly added disk devicesAlternatively, you can specify a ! prefix character to indicate that you want

84 Administering disksDiscovering and configuring newly added disk devicesAdding support for a new disk arrayThe following example illustrates how to

85Administering disksDiscovering and configuring newly added disk devicesSee “Changing device naming for TPD-controlled enclosures” on page 94 for inf

86 Administering disksDiscovering and configuring newly added disk devicesThis command displays the vendor ID (VID), product IDs (PIDs) for the arrays

87Administering disksDiscovering and configuring newly added disk devicesListing supported disks in the DISKS categoryTo list disks that are supported

88 Administering disksDiscovering and configuring newly added disk devices[length=serialno_length] [policy=ap]where vendorid and productid are the VID

89Administering disksDiscovering and configuring newly added disk devicesFor more information, enter the command vxddladm help addjbod, or see the vxd

90 Administering disksPlacing disks under VxVM control Enclosure information is not available to VxVM. This can reduce the availability of any disk g

10 ContentsCreating a concatenated-mirror volume ...249Creating a volume with a version 0 DCO volume ...

91Administering disksChanging the disk-naming scheme If the disk was previously in use by the LVM subsystem, you can preserve existing data while sti

92 Administering disksChanging the disk-naming schemeAlternatively, you can change the naming scheme from the command line. The following commands sel

93Administering disksChanging the disk-naming scheme# vxdmpadm getlungroup dmpnodename=disk25VxVM vxdmpadm ERROR V-5-1-10910 Invalid da-name# vxdmpad

94 Administering disksChanging the disk-naming schemeChanging device naming for TPD-controlled enclosuresNote: This feature is available only if the d

95Administering disksChanging the disk-naming scheme Persistent simple or nopriv disks in the boot disk group Persistent simple or nopriv disks in n

96 Administering disksInstalling and formatting disks3 If you want to use enclosure-based naming, use vxdiskadm to add a non-persistent simple disk to

97Administering disksDisplaying and changing default disk layout attributesDisplaying and changing default disk layout attributesTo display or change

98 Administering disksAdding a disk to VxVMdisks available for use as replacement disks. More than one disk or pattern may be entered at the prompt.He

99Administering disksAdding a disk to VxVM3 To continue with the operation, enter y (or press Return) at the following prompt:Here are the disks selec

100 Administering disksAdding a disk to VxVMA site tag is usually applied to disk arrays or enclosures, and is not required unless you want to use the