RE: Performance problems after moving to new hardware
- From: Upendra nerilla <nupendra@xxxxxxxxxxx>
- To: "sbecker6925@xxxxxxxxx" <sbecker6925@xxxxxxxxx>
- Date: Wed, 4 Mar 2015 17:54:06 -0500
If you are using ZFS for the file system, you may want to find out the zfs
cache settings from a sysadmin. A reasonable value may be about 10% of the
physical memory (assuming the T5 has at least 128G memory).
Also double check if the cache in EMC array is enabled..
accidentally/unintentionally turning it off will yield poor response times..
though rare, worth checking it.
-Upendra
Date: Wed, 4 Mar 2015 15:27:50 -0700
Subject: Re: Performance problems after moving to new hardware
From: sbecker6925@xxxxxxxxx
To: mark@xxxxxxxxxxxxxxxxxxxxxxxxx
CC: oracle-l@xxxxxxxxxxxxx
We migrated from a Dell platform.
Sandy
On Wed, Mar 4, 2015 at 2:24 PM, Mark Burgess <mark@xxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
Hi Sandra,
What was the hardware platform that you migrated this system from? Was it T5 or
other?
Regards,
Mark
> On 5 Mar 2015, at 12:25 am, Sandra Becker <sbecker6925@xxxxxxxxx> wrote:
>
> OS: Solaris Sparc 10 (64-bit)
> Oracle: EE 11.2.0.2
>
> The OS and Oracle versions are identical on both the old and new servers.
> Storage attached to the new server is a new EMC disk array. Sorry I don't
> have any more details on the storage and the only additional information I
> have on the server is that it is a T5.
>
> We created a standby on the new hardware and did a switchover last Friday
> night. On Saturday I completed gathering stats on the application schema
> tables as requested by the product manager. As usual, very little activity
> on this database over the weekend. Yesterday morning we were contacted by
> internal users that performance was much worse than on the old hardware for a
> specific query on a really ugly view. A look at the execution plan shows
> multiple full table scans on some partitioned tables, some very large. There
> are about 15 tables joined to create the view, some more than once. They
> claim the view is no longer doing partition pruning, as it did before the
> switchover. I can't prove that it was/wasn't exhibiting this behavior before
> the switchover. They are insisting we run I/O calibration. I'm not familiar
> with it so I went to the docs. This database shares storage with quite a few
> production databases so I want to be very careful how I go about this.
--
Sandy
GHX
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