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-   -   How to tune vmware server 64 bit with only one 2008 SBS Premium VM guest ? (

Corsari 06-08-2010 04:26 AM

How to tune vmware server 64 bit with only one 2008 SBS Premium VM guest ?
Dear friends,
I'm experiencing slow network performances and other abnormal cpu activities on the guest in subject.

Do you have any tip or configurations to suggest me?

The configuration is pretty nice
Vmserver 64 bit running on ubuntu 64 bit on a xeon quad core server with 8GB RAM and SAS raid made by 4 10000 rpm drives.
There is also a drbd replica on another quad core machine with obviously same OS setup.
Drbd + heartbeat are running on two dedicated gigabit nics by crossed cables (no switches in between)

Both the two boxes have got 4 gigabit nics. On each phisical server, the other two nics are used in bondig to double the bandwidht.
(About this is pretty strange that 100MB file is copied in 30 seconds... and in the next turn we will try just one nic w/o bonding)

The guest has been clean installed as brand new VM. Assigned RAM is 4GB.

There is, and there will be, just and only 1 VM guest in this system.

Ask me more details if u need them.

Thank you for any help.


halvy 06-08-2010 06:12 PM

There are lots of things you can try...
Sorry I don't think I can help much since I'm not a network expert, nor am I familiar with vmserver.

However I do have some experience in these areas (vm, networking, etc.) so here it goes.

This is what I would try and do.. either together or separately.

- strip everything down as much as possible and add one new feature at a time, until you find the culprit.

- since it's deb based.. you should have a plethora of programs to trace your systems actions.

- what fs are you using.. if ext4 it needs to be set up right or it will actually be sloooower than 3.

- I am supposing vmserver is more appropriate for your task than kvm? All I know is, KVM on single system/servers is actually FASTER than on the *regular* OS from the partition!

- kernel config.. is it selected and *tuned* for your project(s)?

- extranious programs, daemons etc. that are using resources, or NOT using them when they should.. again, this is where there should be some programs available in apt to help.. sorry I can not suggest any, since I have not had the opportunity to evaluate any yet significantly.

Either way, lettuce know :)

Corsari 06-09-2010 02:59 AM

Thank u.
Yesterday, doing some tests we discovered what follow

- initially we assigned 2 processors to the VM. Leaving one only drastically changed performances. 2008 SBS startup boot process time with 2 processors was 5 minutes and 30 seconds, with one processor it is now only 3:00 minutes

- after the CPU change, also the network performances increased. Yes now network is faster but with a weird action. This is the test we made and any of you that can explain this I'll thank him/her so much:
We shared one folder on the server and one on our client.
Our test environment is 100 megabit only switch
We had take one file 500MB size, expected average time for copying it is 50 seconds on a 100mbit lan
And here you the weird
Logging in the client and copy the file from client to server taken 60 seconds (not the best, but acceptable). Doing the reverse takes 90 seconds, yes it does "move" but it is a poor network performance.
Now the weird than weird
Loggin in to the server and repeat the copies but from server side
To copy the file from client to server takes 55 seconds while copying from server to that same client takes 45 seconds!!! Peaks were over 11MB/sec

Can u explain this?

I'll update you with next tests.


halvy 06-09-2010 04:30 AM

Try some very similar (the same) *tests* without the VM.

In other words, see what your system specs are (should be), while running your normal operating system...and then match them up against the vm state.

This way you can see if the problem is directly connected to the vm software/state, or not.

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