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chevitom
Contributor
Contributor

Converted Physical Machine low Performance

Hi,

I just converted a physical Machine into a virtual Machine. The virtual Machine is separated on a ESX Host. No others machine is running on this host. The virtual Machine hosts an Oracle Database (Version 8). The user of the Database Application reporting a very low performance, after the migration. When I check the Task Manager of the virtual machine, I recognize that oracle.exe causes up to 100% CPU load on one of the 4 virtual Processors. Obviously the application is not able to scale on multiple CPU´s.

Does anyone has experience in Converting machines with Oracle Databases into vm? During the converting process I stopped the Database Service on the source machine.

Here are some details of the scenario:

Physical Machine:

2x3Ghz CPU

512MB RAM

SCSCI RAID 1

Windows 2000 Server Standard SP4

virtual Machine

4 Processors

512MB RAM

ESX Server 3.5

4 Dual Core Xeon 2,33 Ghz

32GB RAM

4GBit FC SAN

In my opinion the vm must have enough power to run the database.

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wila
Immortal
Immortal

When I check the Task Manager of the virtual machine, I recognize that oracle.exe causes up to 100% CPU load on one of the 4 virtual Processors. Obviously the application is not able to scale on multiple CPU´s.

But if you create a VM with 4 vCPUs, your VM will still have to wait on having 4 CPUs available at the same time for the scheduler in order to run that single process.

As you can imagine that will add some latency and if your VM is not going to compensate this by running on 4 vCPUs, then your VM (and host and all other VMs at that host) will be better off with just one vCPU. Yes I did see it is only one VM now, but if you have enough power, i assume you will want to add more VMs.

So I'd suggest you change your tactic and start with ONE vCPU and scale upwards if there's not enough power.

As you are talking about a P2V operation, have you removed the obsolete hardware and accompanying management software?

See: http://www.vmware-land.com/Converter.html step 9 for details

Additionally why is your VM setup with only 512MB if you have 32GB available... give it more memory, Oracle loves more memory.

--

Wil

| Author of Vimalin. The virtual machine Backup app for VMware Fusion, VMware Workstation and Player |
| More info at vimalin.com | Twitter @wilva
chevitom
Contributor
Contributor

Hi wila,

thanks for your reply. I just gave the machine only 1 CPU and 2GB memory. The obsolete hardware (serial, usb etc.) was removed bevore the vm was started the first time. I also checked the Converter Website you provided me for new hints.

But the performance ist not better now.

Maybe you have another idear?

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wila
Immortal
Immortal

I just gave the machine only 1 CPU and 2GB memory.

Did you switch the HAL as well back to an ACPI uniprocessor? (Right click My Computer -> Hardware -> device manager -> Computer)

>The obsolete hardware (serial, usb etc.) was removed bevore the vm was started the first time.

Um, how do you do that? I'm not talking about the virtual hardware setup of your VM, but about removing driver left over residue from now obsolete hardware in your guest operating system. Drivers used in your physical system. Leaving those in your VM can cause all kinds of "funny" behavior.

Optimizing Oracle by itself is a specialist task that is a tad bit hard to answer without more background info, ideally you would want to discuss this with your Oracle administrator group.

You likely want to repost your question (with more background info like approx size of your database, oracle version used, etc...) over here:

http://communities.vmware.com/community/vmtn/general/oracle

--

Wil

| Author of Vimalin. The virtual machine Backup app for VMware Fusion, VMware Workstation and Player |
| More info at vimalin.com | Twitter @wilva
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BenConrad
Expert
Expert

Do you have a single or multi-processor HAL? If you had 2 or 4 CPU's and are now down to 1 CPU you still have the MP HAL. Switch to the Uni-proc HAL. Also, since you P2V'ed, make sure you don't have a Buslogic SCSI adapter, change it to LSILogic

Ben

chevitom
Contributor
Contributor

Hi,

we decided to bring the physical system back to life. The next time we will try to convert a physical database system we try the cold-clone method. Thank you for your support.

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