RE: Performance problems after moving to new hardware

From: Upendra nerilla <nupendra_at_hotmail.com>
Date: Wed, 4 Mar 2015 17:54:06 -0500
Message-ID: <BLU181-W77CBE1A32FFC058CAA5381D81E0_at_phx.gbl>

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_at_gmail.com
To: mark_at_burgess-consulting.com.au
CC: oracle-l_at_freelists.org

We migrated from a Dell platform.

Sandy

On Wed, Mar 4, 2015 at 2:24 PM, Mark Burgess <mark_at_burgess-consulting.com.au> 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_at_gmail.com> 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
--

http://www.freelists.org/webpage/oracle-l Received on Wed Mar 04 2015 - 23:54:06 CET