HP IO Accelerator for BladeSystem c-Class Performance Tuning Manuel d'utilisateur télécharger pdf (Page 22)

Linux filesystem tuning 22

(stride) 32K = 256K / 8K

(dbd) 4 = 5 - 1

(stripe_width) 128 = 4 * 32K

This results in the following command:

$ mkfs.ext3 -b 8192 -E stride=32 -E stripe_width=128 /dev/md0

For more information on setting the stripe size, see the article "Optimizing the EXT3 file system on CentOS

(http://wiki.centos.org/HowTos/Disk_Optimization)."

Using the IO Accelerator as swap space

NOTE: Adding multiple swap partitions usually slows down swap performance, even if they are

set at the same priority. For best performance, only use one IO Accelerator device as swap space.

To safely use the IO Accelerator as swap space requires passing the preallocate_memory kernel module

parameter. The recommended method for providing this parameter is to add the following line to the

/etc/modprobe.d/iomemory-vsl.conf file:

options iomemory-vsl preallocate_memory=1072,4997,6710,10345

Where 1072, 4997, 6710, and 10345 are serial numbers obtained from the fio-status utility.

A 4 KiB sector size format is required for swap. This reduces the driver memory footprint to reasonable levels.

Use the Management Tool or the fio-format utility to format the IO Accelerator with 4 KiB sector sizes.

CAUTION: You must have 400 MiB of free RAM per 80GB of IO Accelerator capacity

(formatted to 4 KiB block size) to enable the IO Accelerator with pre-allocation enabled for use as

swap. Attaching an IO Accelerator with pre-allocation enabled without sufficient RAM may result

in the loss of user processes and system stability.

NOTE: Be sure to provide the serial numbers for the IO Accelerators, not the adapter.

NOTE: The preallocate_memory module parameter is necessary to have the drive usable as

swap space. See the HP IO Accelerator User Guide for Linux for more information on setting this

parameter.

NOTE: The preallocate_memory parameter is recognized by the IO Accelerator driver at

load time, but the requested memory is not actually allocated until the specified device is

attached.

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 32 33

Pas de commentaire

HP IO Accelerator for BladeSystem c-Class Performance Tuning Manuel d'utilisateur Page 22