Re: Oracle on windows 2003 on vmware

Tis the season for interesting decisions!

Your post has reminded me that I need to write up and make generally
available my tests of performance on Linux/Windows with and without VMWare.
The executive summary is that the choice of OS doesn't really make a blind
bit of difference to Oracle performance - Linux scales a bit better but at
realistic loads there's not really anything to make a choice, and
relevantly here that there is a real and quite significant performance hit
for running on VMware that likely means you'll only want to do this for low
impact or non-performance critical databases. I've just looked quickly and
it looks to me that for comparable loads I found VMWare to generate about
50% of the throughput of a dedicated server. The Vmware hardware and the
dedicated hardware weren't actually comparable though so don't rely on that
info too much.

One thing that I didn't test and I would expect to significantly impact
performance - especially with issues like yours - is the difference that is
made by allowing VMware to see the disk directly rather than through the OS
that is hosting ESX. If you've created VMWare Disks on your mount points it
might be worth dedicating them to the VM that is running oracle and rerun.

On 1/3/07, Ron Rogers <RROGERS@xxxxxxxxxxxxx> wrote:


Our corporate wiz kid has decided to migrate our Oracle 10g database from
Linux to Windows2003 on Vmware.

Are there any special setup instruction needed to make this work properly?
Any references that I might have missed? I searched the OTN but did not find
anything that jumped out at me.

Linux server. 1 CPU, 4 GIG ram, 3 internal mount points for data.  Oracle
setup with 1.6 GIG SGA

Windows VMWARE server. 1 CPU, 4 GIG ram, 3 mount points on SAN(2 fiber
channel 1 SATA) data. Oracle setup with 1.6 GIG SGA

Both servers have the same tables, partitions, and data loaded on one
mount point. In the Windows case it is the SATA SAN.

I set timing on.

I run the query select count(*) from a table that has 500,000,000 records

 Linux = 4 min, 24.83 seconds

Windows = 19 min,53.19 seconds

The results are proportionatly the same for the other tables that have
millions of records.

Is there any helpful hints that we might have missed when we set up the
VMWARE ESX server for windows/oracle?

When I google for VMWARE and Oracle the results are for Linux and RAC not
windows. Maybe they are trying to tell me something.

Any usefull suggestions?


Ron Rogers


Georgia Lottery Corp.



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Niall Litchfield
Oracle DBA

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