Incredibly high disk latency

[xinoid]

At first it happened on esxi 5.0, 469512. Then I updated it to esxi 5.1.0, 1117900

It worked well for some time and now it appeared again. I have serious performance problems.

My configuration:

Dell poweredge R610, 196 GB Ram.

At the moment this VM resides on local datastore, raid 50, 6 disks

The problem also happens even if I migrate VM to other datastore.

System health is good as shown at hardware status.

Please help!

[JimKnopf99]

Hi,

could you tell more about your vm?

OS, size, application running.......

Does only this VM has Problems?

Are other VM´s running on the same machine?

What are These VM´s are? OS ....

Frank

[xinoid]

This vm 's guest is windows 2003 server. With Domain Controller, File server and Microsoft SQL server 2000. 3 gb Ram, 260 gb disk.

It is also replicated every hour.

At the moment only this VM has problems. Other vms are ok(Almost every is Windows XP). But earlier, when I had esxi 5.0, this problem also appeared on some other vms.

Strange thing also, that this peak of disk latency does not appear in custom statistic report for a week.

[khaliqamar]

adding some more point to Frank's reply.

you have to check when actually it started.

via esxtop  check davg is it >20 ? if it is you may have a  problem on storage side.

did you change something recently on your antivirus or any application configuration?

Regards,

[xinoid]

davg fluctuates between 2 and 22 at approximately. Once it go 50.

Nope, nothing was changed. It worked well for 1 month. And now same thing!

[JimKnopf99]

Hi,

also check, if your Windows disk is aligned.

That is important an Windows Server 2003 does not align disk automaticaly.

https://communities.vmware.com/thread/425590

Frank

[khaliqamar]

Is this problem with only one VM in a datastore ?

check your antivirus and other applications. try to disable it and check if it makes any difference.

[JimKnopf99]

And of course 3 GB of RAM could be insufficent.

Because of your apps running on that Server.

Check Memory swapping for your guest os.

Frank

[xinoid]

update. Today I have been told that every VM has performance issues, even when opening simple documents.

I collected some esxtop statistics and that's what I've got:

Y axis is CMDs per second.

I have 6 10k sas drives in raid50, and total IOPS value without raid penality is 780.

Does that mean that disks are bottleneck?