Re: Experience with HP Smart Array P400 and SATA drives? - Mailing list pgsql-performance

From Alan Hodgson
Subject Re: Experience with HP Smart Array P400 and SATA drives?
Date
Msg-id 200812051530.01258@hal.medialogik.com
Whole thread Raw
In response to Re: Experience with HP Smart Array P400 and SATA drives?  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Experience with HP Smart Array P400 and SATA drives?  (Greg Smith <gsmith@gregsmith.com>)
Re: Experience with HP Smart Array P400 and SATA drives?  (Mario Weilguni <mweilguni@sime.com>)
List pgsql-performance
> >>> Mario Weilguni <mweilguni@sime.com> wrote:
> > strange values. An individual drive is capable of delivering 91
> > MB/sec
>
> > sequential read performance, and we get values ~102MB/sec out of a
> > 8-drive RAID5, seems to be ridiculous slow.


What command are you using to test the reads?

Some recommendations to try:

1) /sbin/blockdev --setra 2048 device (where device is the partition or LVM
volume)

2) Use XFS, and make sure your stripe settings match the RAID.

Having said that, 102MB/sec sounds really low for any modern controller with
8 drives, regardless of tuning or filesystem choice.

--
Corporations will ingest natural resources and defecate garbage until all
resources are depleted, debt can no longer be repaid and our money becomes
worthless - Jay Hanson

pgsql-performance by date:

Previous
From: "Scott Marlowe"
Date:
Subject: Re: Experience with HP Smart Array P400 and SATA drives?
Next
From: Greg Smith
Date:
Subject: Re: Experience with HP Smart Array P400 and SATA drives?