Configure and Customize Dell PowerFlex v3.6.x

Paravirtual SCSI controller

The Paravirtual SCSI (PVSCSI) controller should be used on guest VMs for high performance. It is important that users choose the correct PVSCSI controller, because choosing the wrong controller can adversely affect performance.

Current PVSCSI queue depth default values are 64 for the device and 254 for the adapter. Users can increase the PVSCSI queue depth to 256 for the device and 1024 for the adapter inside a Windows virtual machine.

Windows virtual machine:

1. From the command line run:

   REG ADD HKLM\SYSTEM\CurrentControlSet\services\pvscsi\Parameters\Device /v DriverParameter /t REG_SZ /d "RequestRingPages=32,MaxQueueDepth=254"

2. Reboot the virtual machine.
3. Verify the successful creation of a registry entry:
   1. Open the registry editor by running the REGEDIT command from the command line.
   2. Browse to HKLM\SYSTEM\CurrentControlSet\services\pvscsi\Parameters\Device.
   3. Verify that the DriverParameter key exists with a value of RequestRingPages=32, MaxQueueDepth=254.

Linux guests:

1. Edit the vmw_pvscsi.conf file:

   echo "options vmw_pvscsi cmd_per_lun=254 ring_pages=32" > /etc/modprobe.d/vmw_pvscsi.conf

2. Re-run vmware-config-tools.pl:

   vmware-config-tools.pl

You can add up to 4 PVSCSI controllers per guest. Allocating different PowerFlex volumes to different PVSCSI controllers can help realize the maximum potential of guest performance.

It is strongly recommended that you review this VMware Knowledge Base article (article 2053145) so that you can make educated decisions regarding PVSCSI values.