Hi,

I recently changed from an Adaptec 3405 controller to an onboard ATI SB600 controller (ASUS M2A-VM motherboard)

The controller is running in AHCI mode, and I have a couple of VMs running fine on it.

However; When I try to start or install a Windows 6.x guest with LSI Logic controller, disk latency spikes to above 50ms - and the guest is virtually unusable.

- I have tried with Win7, Server 2008 and Server 2008 R2 guests. (32/64bit)
- Tried LSI SAS and parallel controllers.
- Tried two different physical disks as datastores.
- I have tried upgrading ESXi from U1 to U2

I have a Server 2008 with VMWare Paravirtual SCSI running just fine.

Any ideas?

Best regards
Martin

Well: A BIOS-upgrade plus ESXi upgrade to v4.1 did me no good.
- Except that power consumption of the server rose by 50%

Due to the new performance counters in ESXi 4.1 i did however discover that latency of the individual virtual disks was MUCH higher than overall physical disk latency - and that linux OS'es were affected by the problem as well.

In fact my SUSE based firewall (Astaro) had an average virtual disk write latency of 90ms!
(Which explained why the webGUI was so slow.)

I changed to buslogic controller, since paravirtual didn't work.
After that latency was down to single digit levels.

So for now I'm giving up LSI and sticking with paravirtual/buslogic.

Best regards.

Martin