[PVE-User] poor HDD performance

[Patryk Benderz]

Dnia 2013-05-23, czw o godzinie 19:18 +0200, Vassilis V. pisze:
> A very wild guess...
> 
> Are you sure that both servers have a BBU on their raid controllers and
> both controllers have write cache enabled?
	BBU? Is this Backup Batterry Unit? If so, then no, both cards do not
have BBU. According to this [1] they are low-end cards, supporting only
RAID0 and RAID1. While this page is about SAS1068, and I have SAS1064E,
I assume my both cards do not have cache.
	I will try to activate disk caches, as advised by Dietmar in this
thread [2]. Any hints on how to activate HDD cache, maybe I can do it
with hdparm?

Both cards look the same at lspci output:
'fast' card:
proxmox218:~# lspci -nn -s 01:00.0
01:00.0 SCSI storage controller [0100]: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS [1000:0056] (rev 02)
slow card:
root at pve:/# lspci -nn -s 05:00.0
05:00.0 SCSI storage controller [0100]: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS [1000:0056] (rev 02)

[1] http://hwraid.le-vert.net/wiki/LSIFusionMPT
[2] http://forum.proxmox.com/threads/2896-Bad-Performance-High-IO-Delay

-- 
Patryk "LeadMan" Benderz
Linux Registered User #377521
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