A couple of months ago at the Dutch VMug meeting Bouke-Jumé gave some good storage tips. This is one of them:
The LSI Bus Logic Controller / Driver has a standard queue depth of 256. Although it isn’t possible to set this higher it is possible to add a second controller and when you make sure the SCSI ID of your disk corresponds to the SCSI card you will have another queue of 256. This can lead to improved performance for Database Servers, Fileservers and other I/O intensive VM’s.
Open the properties of the VM,
For the first disk and SCSI Controller 0 go to the virtual disk and select 0:X
For the second disk and SCSI Controller 1 go to the virtual disk and select 1:X
And so on…
vSphere 4.0 Quick Start Guide
Do you have a example VMX file for this?
I would like to see this in more detail.
Roger L
FYI…
When adding an additional disk on a “2nd” Controller you will not see the 1:x option when the VM is powered on. Powerdown the VM and you will be able to add disks on the 0:x, 1:x, 2:x and 3:x