We have been trying to pinpoint what originally seem to be a I/O bottleneck but which now seems to be an issue with either Postgresql or RHES 3.
We have the following test environment on which we can reproduce the problem:
1) Test System A
Dell 6650 Quad Xeon Pentium 4
8 Gig of RAM
OS: RHES 3
On 30-Aug-05, at 12:15, Tom Lane wrote:
=?ISO-8859-1?Q?R=E9my_Beaumont?= [EMAIL PROTECTED] writes:
The stats of the NetApp do confirm that it is sitting idle.
Really?
CPU NFS CIFS HTTP TotalNet kB/s Disk kB/s Tape kB/s
Cache Cache CP CP Disk DAFS FCP iSCSI
On Mon, Aug 29, 2005 at 09:42:46AM -0400, Rémy Beaumont wrote:
We have been trying to pinpoint what originally seem to be a I/O
bottleneck but which now seems to be an issue with either Postgresql or
RHES 3.
Nope, it's an IO bottleneck.
The behavior we see is that when running queries that
=?ISO-8859-1?Q?R=E9my_Beaumont?= [EMAIL PROTECTED] writes:
The stats of the NetApp do confirm that it is sitting idle.
Really?
CPU NFS CIFS HTTP TotalNet kB/s Disk kB/s Tape kB/s
Cache Cache CP CP Disk DAFS FCP iSCSI FCP kB/s
in
=?ISO-8859-1?Q?R=E9my_Beaumont?= [EMAIL PROTECTED] writes:
On 30-Aug-05, at 12:15, Tom Lane wrote:
I know zip about NetApps, but doesn't the 8th column indicate pretty
steady disk reads?
Yes, but they are very low.
Sure, but that's more or less what you'd expect if the thing is randomly
On 30-Aug-05, at 12:29, Tom Lane wrote:
=?ISO-8859-1?Q?R=E9my_Beaumont?= [EMAIL PROTECTED] writes:
On 30-Aug-05, at 12:15, Tom Lane wrote:
I know zip about NetApps, but doesn't the 8th column indicate pretty
steady disk reads?
Yes, but they are very low.
Sure, but that's more or less
Remy,
The behavior we see is that when running queries that do random reads
on disk, IOWAIT goes over 80% and actual disk IO falls to a crawl at a
throughput bellow 3000kB/s (We usually average 4 kB/s to 8 kB/s
on sequential read operations on the netapps)
This seems pretty low for a
BeaumontSent: Monday, August 29, 2005 9:43 AMTo:
pgsql-performance@postgresql.orgSubject: [PERFORM] High load and
iowait but no disk access
We have been trying to pinpoint what originally seem to be a I/O
bottleneck but which now seems to be an issue with either Postgresql or RHES
3.We have
On 30-Aug-05, at 14:32, Josh Berkus wrote:
Remy,
The behavior we see is that when running queries that do random reads
on disk, IOWAIT goes over 80% and actual disk IO falls to a crawl at a
throughput bellow 3000kB/s (We usually average 4 kB/s to 8
kB/s
on sequential read
-performance@postgresql.org
Subject: Re: [PERFORM] High load and iowait but no disk access
Have you tried a different kernel? We run with a netapp over NFS
without any issues, but we have seen high IO-wait on other Dell boxes
(running and not running postgres) and RHES 3. We have replaced
?
Thanks,
Anjan
From: Woody Woodring
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, August 30, 2005
2:30 PM
To: 'Rémy Beaumont';
pgsql-performance@postgresql.org
Subject: Re: [PERFORM] High load
and iowait but no disk access
Have you tried a different kernel?
We run with a netapp over NFS
]
Sent: Tuesday, August 30, 2005 2:30 PM
To: 'Rémy Beaumont'; pgsql-performance@postgresql.org
Subject: Re: [PERFORM] High load and iowait but no disk access
Have you tried a different kernel? We run with a netapp over NFS without any
issues, but we have seen high IO-wait on other Dell
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