RE: ASM+internal disks
- From: "Vishal Gupta" <vishal@xxxxxxxxxxxxxxx>
- To: <ora_kclosson@xxxxxxxxx>, "Oracle-L" <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 26 Apr 2011 17:16:33 +0100
On RHEL5, CFQ i/o scheduler is broken. Under heavy load performance improves
with deadline i/o scheduler. On RHEL4 it does not give much benefit. There is
linux bug for broken CFQ on RHEL5.
http://www.google.co.uk/url?sa=t&source=web&cd=1&sqi=2&ved=0CBYQFjAA&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D456181&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNEKaFfKVmLhVeoMgJzoaGyeRXS15w
http://www.google.co.uk/url?sa=t&source=web&cd=2&sqi=2&ved=0CBwQFjAB&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D427709&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNEZHzLC3u7lkB3nE-1ZNbI7hvboFQ
http://www.google.co.uk/url?sa=t&source=web&cd=3&sqi=2&ved=0CCIQFjAC&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D448130&rct=j&q=redhat%20cfq%20bug%20i%2Fo%20slow&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNGdlO8BfKyUeWrifJLtybLszRGsBg
Regards,
Vishal Gupta
http://www.vishalgupta.com
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Kevin Closson
Sent: Tue 26/04/2011 16:45
To: Oracle-L
Subject: Re: ASM+internal disks
Here's how I look at this. The following are true 1) there is no networked
storage so all disks are the same, 2) the database is important and 3) the
Oracle software and OS are equally important. Also, in spite of the fact that I
got no information back regarding how the disks are attached (e.g., the make
and model of the RAID card) I think we can all be quite certain that the card
supports HW raid. To that end, I would simply configure all 8 drives in a HW
raid configuration. I see no benefit in the slice and dice. I also see no value
in ASM in such a situation but I suppose this could be standard edition or some
other such software that forces its use?
So, Niall, we agree: "...software RAID? Seriously?" :-)
________________________________
From: Niall Litchfield <niall.litchfield@xxxxxxxxx>
To: oracle.tutorials@xxxxxxxxx
Cc: Oracle-L <oracle-l@xxxxxxxxxxxxx>
Sent: Tue, April 26, 2011 12:10:01 AM
Subject: Re: ASM+internal disks
Deepak, I'm with you on the mirrored pair for the o/s - availability trumps the
performance that Kevin refers to. But software RAID? Seriously? Does the server
not have a decent controller? You can of course keep any oracle files outside
of ASM.
On 25 Apr 2011 19:28, "DBA Deepak" <oracle.tutorials@xxxxxxxxx> wrote:
Hi,
We have a server with 8 SAS internal disks. The OS is going to be RHEL
5 x86_64
We plan to mirror disk 1 and 2 using software RAID -- OS and Oracle
software will be kept on this
Remaining 6 disks will be used for ASM.
Need your expert opinion on how to use the disks efficiently to
maximize the available space without loosing ASM performance benefits much.
Our main worry is that if we spare 2 disks for storing online REDO logs
(different ASM diskgroup with fine striping) then it will be a loss of space as
well as we will have only 4 disks to store remaining oracle database files
hence loosing performance a bit.
Please suggest how should we layout the various files under ASM.
--
Regards,
Deepak
Oracle DBA
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