zfs discuss - Aug 2007 - Performance Tuning - ZFS, Oracle and T2000

Hi All,

We are currently in the process of testing Solaris 10 with ZFS and 
Oracle and are running it on a T2000.

When checking performance statistics on the T2000, we notice that only 
one thread of the CPU appears to be doing any of the processing.  
Leaving all other threads seemingly idle.

Are there any tuning parameters that need to be set or changed when 
running Oracle on T2000 using ZFS?  Can anyone suggest what I might look 
for? 

Any initial suggestions would be greatly appreciated.

Regards,

Damian Reed

http://blogs.sun.com/realneel/entry/zfs_and_databases

http://www.sun.com/servers/coolthreads/tnb/parameters.jsp

http://www.sun.com/servers/coolthreads/tnb/applications_oracle.jsp

Be careful with long running single queries...  you want to throw lots
of users at it ... or parallelize as much as possible!

Also keep in mind that a T2000 running flat out has the potential to
generate LOTS of I/O... it''s vital to have a decent storage system
supporting it.

On 8/19/07, Damian Reed - Systems Support Engineer <Damian.Reed at
sun.com> wrote:
> Hi All,
>
> We are currently in the process of testing Solaris 10 with ZFS and
> Oracle and are running it on a T2000.
>
> When checking performance statistics on the T2000, we notice that only
> one thread of the CPU appears to be doing any of the processing.
> Leaving all other threads seemingly idle.
>
> Are there any tuning parameters that need to be set or changed when
> running Oracle on T2000 using ZFS?  Can anyone suggest what I might look
> for?
>
> Any initial suggestions would be greatly appreciated.
>
> Regards,
>
> Damian Reed
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
>

On Sun, Aug 19, 2007 at 09:32:02AM +0200, Louwtjie Burger
wrote:
> http://blogs.sun.com/realneel/entry/zfs_and_databases
> 
> http://www.sun.com/servers/coolthreads/tnb/parameters.jsp
> 
> http://www.sun.com/servers/coolthreads/tnb/applications_oracle.jsp
> 
> Be careful with long running single queries...  you want to throw lots
> of users at it ... or parallelize as much as possible!
> 
> Also keep in mind that a T2000 running flat out has the potential to
> generate LOTS of I/O... it''s vital to have a decent storage system
> supporting it.
> 
> On 8/19/07, Damian Reed - Systems Support Engineer <Damian.Reed at
sun.com> wrote:
> > Hi All,
> >
> > We are currently in the process of testing Solaris 10 with ZFS and
> > Oracle and are running it on a T2000.
> >
> > When checking performance statistics on the T2000, we notice that only
> > one thread of the CPU appears to be doing any of the processing.
> > Leaving all other threads seemingly idle.
> >
> > Are there any tuning parameters that need to be set or changed when
> > running Oracle on T2000 using ZFS?  Can anyone suggest what I might
look
> > for?
> >
> > Any initial suggestions would be greatly appreciated.
> >
> > Regards,
> >
> > Damian Reed
The following page might also be helpful:
http://blogs.sun.com/ValdisFilks/entry/improving_i_o_throughput_for

Regards
przemol

--
http://przemol.blogspot.com/


























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Damian,
Are you using compression=on? There was a bug in the past (fixed
now) where if compression was turned on, it was being computed by a
single thread. The ZFS team fixed the "user data" part of it (i.e 
user data is compressed in parallel now), but the meta data part
is still compressed by one thread. I suspect this might be the
issue. One tunable you can try experimenting with is 
zfs_mdcomp_disable
(http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6485204)

If you can get a kernel stack for this cpu, that would greatly help
in identifying the issue. This can be hard, as the thread could
migrate :-)

hth,
-neel




On Sun, Aug 19, 2007 at 04:41 PM +1000, Damian Reed - Systems Support Engineer
wrote:
> Hi All,
> 
> We are currently in the process of testing Solaris 10 with ZFS and 
> Oracle and are running it on a T2000.
> 
> When checking performance statistics on the T2000, we notice that only 
> one thread of the CPU appears to be doing any of the processing.  
> Leaving all other threads seemingly idle.
> 
> Are there any tuning parameters that need to be set or changed when 
> running Oracle on T2000 using ZFS?  Can anyone suggest what I might look 
> for? 
> 
> Any initial suggestions would be greatly appreciated.
> 
> Regards,
> 
> Damian Reed
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss