Windows Server 2003 4-vProcs ESX 3i

[TCG]

I created a new VM with windows server 2003 and assigned it 4 vProcs. For some reason with 4 procs is boots very slow as compared with 2 or even 1 proc. 1 proc boots the fastest. Also a wierd issue occurs on reboot, the screen will go black and stay that way for about 10-15 seconds before the VMWare post screen pops back up and it can take anywhere from 20-60 seconds for the VM to boot. This is not a problem with 1 or 2 procs. The boot gets a second or two longer with 2 procs vs 1. I checked performance data to make sure none of the other VMs had things pegged out and overall resources where very low. I tried both x86 and x64 version of Windows Server 2003 Ent R2 with the same result, and varying amounts of ram.

Once the 4-proc VM boots it seems to run just fine and fast but the boots and reboots seem to be erratic.

Is this a bug or is there a config option i need to change?

Server config:

(2) Quad Xeons @ 2.5 GHz E5420

32GB DDR2 FB ram

(2) 73GB 15k SAS Raid1

(8) 300GB 15k SAS Raid10

(2) Broadcom Onboard Gb NICs (i hate broadcom)

Thanks

[Dave_Mishchenko]

When you start up a VM it will typically cause a cpu spike until the os starts to boot. If you host is busy, the spike could be exagerated because esx has to find 4 CPU cores that are free at the same time to process each cpu cycle for the VM. When you're booting single or dual vCPU VM, ESX only has to find one or two free cpu cores at a time. That's the downside to running dual or quad vCPU vms and performnce can realy degrade if the host is busy.

Do you have the remote commnd line interface for 3i installed somewhere. If so, run resxtop and see what the cpu wait times are for this vm when you start it. If it's high, then ESX is having problems scheduling 4 free cpu cores at the same time to service this VM. If you don't have the RCLI installed, see this link for adding the RCLI appliance - http://www.vm-help.com/esx/esx3i/Import_RCLI_Appliance.html

[TCG]

That makes sense. I downloaded and imported the appliance and ran the command listed but i get an error

Error during version check: No such file or directory(2): /dev/vmkcall doesn't exist.

I am logged in as root. Do you have to install any packages? Is there any documentation on the CLI?

Thanks

[Smeagol]

There are some intesting dell documents about Exchange 2007 processor scaling on vmware

http://www.dell.com/downloads/global/power/ps4q07-20080147-Muirhead.pdf

Unless you really need 4vCPU's you may be better off with less.

For the CLI you have to set some environment and variable values. Its in an appendix of the 3i guide

http://www.vmware.com/pdf/vi3_35/esx_3i_e/r35/vi3_35_25_3i_server_config.pdf

[spex]

8 cores in your server should give the kernel enough cpu's (also 4 for one vm) under normal circumstances. The differences shouldn't be so dramatic.

Check articel for your esx server configuration.

The articel talks about network performance, but the underlying problem could also led to the problems you have. Heavily loaded first core for all vm's doing io.

Regards

Spex