One VM use extreme I/O and reduce performance of the other VM

[radeontof]

Dear all,

here my esx config :

esx 3.0.1

Tyan VX50 with 4x880 opterons

16 go ram

Adaptec S2820SA with 8 SATA DISK in RAID 5EE

3 VM : Windows server 2003 R2 64bits (Domain controller), Windows 2000 server (sql 2000) and windows 2003 standard R2 ( Terminal server / applications)

When the backup of the night is finish (finish at 9:00...) the sql database is updated and use a lot of I/O during a lot of time.

During this time, the performance on the Terminal server (7 users for now but will upgrade to 25 users) is poor/horrible.

I don't know what to do, because the next VM will be a exchange 2007 and i think it will be worst in the I/O.

What is for you the best solution ?

- Destroy the raid 5 , reinstall everything on multiple raid1 ? (1 raid1 by machine...? Esx supports that?)

- Add an external hard disk system where i can move the sql or the tse vm ?

- others ideas?

Thanks for your help.

ToF

[jp-H · Accepted solution]

Hi radeontof,

Unfortunately, RAID 5 is not the fastest system for high I/O activity.

Can you isolate the VM using a lot of I/O in a separate datastore -and/or- disk controler ?

To have a maximum speed, it is a good idea to separate VM on multiple datastores. for example 1 or 2 VM by datastore if possible.

In fact each volume (RAID 1 for example) can be a separate VMFS datastore. Then you can create each VM in a datastore if you want.

If you put a lot of VM in a unique datastore, all the I/O of all the VM are added to access this datastore. It seems to be your problem.

Another possibility is to add another controler to separate I/Os. Each controler can manage a volume.

Is there any RAM in your controler ? caching I/Os is also a good solution.

You have a lot of solutions, all depends of your hardware, and how you want to manage it.

Good luck !

[jccoca]

You can make a RAID1 for SQL VM and RAID 5 for the others. How many I/O are the SQL VM using?

[EGRAdmin]

With your windows 2000 SQL server.

If you upgrade to windows 2003 and SQL 2000 SP4 then upgrade your VMware tools your resource utilization should improve.

I experienced similiar issues with systems running DB2 / SQL on Windows 2000 (and 2000 advanced).

What you can also try doing is setting up a strict resource policy for the DB server.

[radeontof]

Thanks all for your answer.

For now, i have only one controller in the server. I think i will use the multiple raid1 solution to have multiple datastore.

For the reinstall, i need to reinstall anything ? Can i zip all my vmfs, move using winscp to a windows hard drive, reinstall the esx server (can i put directly the 3.0.2 now, or upgrade after ?) , create the datastores then.... unzip my vmfs on differents datastore, attach all the vmfs....and start everything...

I know it's a lot of question but i'm novice in the vmware and don't want to do mistakes!

Thanks.