Optimizar Dell SAS Raid

Utilizando un servidor Dell: PowerEdge SC440

Con RAID: LSI SAS 1068 PCI-X

root@fastfoot-ng:~# lspci | grep -i SAS
02:08.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068 PCI-X Fusion-MPT SAS (rev 01)

Y Sistema Operativo: Ubuntu Feisty

Se ha detectado que el acceso a disco con el RAID activado es demasiado lento, así que … buscado y buscando se ha conseguido mejorar el acceso a disco: http://www.tomasek.cz/software/SAS5iRperf/index.html http://www.tomasek.cz/software/dellstuff/

Así que…

root@maquina:~# sync ; time (dd if=/dev/zero of=bigfile count=1024 bs=1M; sync)
1024+0 registros de entrada
1024+0 registros de salida
1073741824 bytes (1,1 GB) copiados, 12,492 segundos, 86,0 MB/s

real    0m48.029s
user    0m0.000s
sys     0m1.256s
root@maquina:~# sync ; time (dd if=/dev/zero of=bigfile count=1024 bs=1M; sync)
1024+0 registros de entrada
1024+0 registros de salida
1073741824 bytes (1,1 GB) copiados, 12,2961 segundos, 87,3 MB/s

real    0m50.405s
user    0m0.008s
sys     0m1.708s

Es tan simple como descargar lsutil http://www.tomasek.cz/software/dellstuff/lsiutil-1.38.tar.bz2

Se descomprime, compila y ejecuta:

root@maquina:~# cd /usr/local/src
root@maquina:~# wget http://www.tomasek.cz/software/dellstuff/lsiutil-1.38.tar.bz2
root@maquina:~# tar jxvf lsiutil-1.38.tar.bz2
root@maquina:~# cd lsiutil
root@maquina:~# make

Lo ejecutamos:

root@maquina:~# ./lsiutil 

LSI Logic MPT Configuration Utility, Version 1.38, July 6, 2005

1 MPT Port found

     Port Name         Chip Vendor/Type/Rev    MPT Rev  Firmware Rev
 1.  /proc/mpt/ioc0    LSI Logic SAS1068 B0      105      00063200

Select a device:  [1-1 or 0 to quit]

Pulsamos 1

 1.  Identify firmware, BIOS, and/or FCode
 2.  Download firmware (update the FLASH)
 4.  Download/erase BIOS and/or FCode (update the FLASH)
 8.  Scan for devices
10.  Change IOC settings (interrupt coalescing)
13.  Change SAS IO Unit settings
16.  Display attached devices
20.  Diagnostics
21.  RAID actions
22.  Reset bus
23.  Reset target
30.  Beacon on
31.  Beacon off
97.  Reset SAS phy
98.  Reset SAS link
99.  Reset port

Main menu, select an option:  [1-99 or e for expert or 0 to quit] 

Pulsamos 21

 1.  Show volumes
 2.  Show physical disks
 3.  Get volume state
23.  Replace physical disk
30.  Create volume
31.  Delete volume
32.  Change volume settings

RAID actions menu, select an option:  [1-99 or e for expert or 0 to quit] 

Pulsamos 32

Volume:  [0-1 or RETURN to quit]

Pulsamos 0

Volume 0 Settings:  write caching enabled, auto configure, priority resync
Volume 0 draws from Hot Spare Pools:  0

Enable write caching:  [Yes or No, default is No] 

Escribimos Yes

Offline on SMART data:  [Yes or No, default is No] 
Auto configuration:  [Yes or No, default is Yes] 
Priority resync:  [Yes or No, default is Yes] 
Hot Spare Pools (bitmask of pool numbers):  [00 to FF, default is 01] 

RAID actions menu, select an option:  [1-99 or e for expert or 0 to quit] 

Pulsamos 0, hasta salir del programa.

Listo, ya esta habilitada la cache.

root@maquina:~# sync ; time (dd if=/dev/zero of=bigfile count=1024 bs=1M; sync)
1024+0 registros de entrada
1024+0 registros de salida
1073741824 bytes (1,1 GB) copiados, 6,27473 segundos, 171 MB/s

real    0m23.095s
user    0m0.008s
sys     0m1.728s
root@maquina:~# sync ; time (dd if=/dev/zero of=bigfile count=1024 bs=1M; sync)
1024+0 registros de entrada
1024+0 registros de salida
1073741824 bytes (1,1 GB) copiados, 6,23949 segundos, 172 MB/s

real    0m21.212s
user    0m0.008s
sys     0m1.688s

La mitad de tiempo ;)