VMware Paravirtual SCSI Controller

According to VMware, there are two main reasons to deploy a virtual machine with the Paravirtual SCSI controller:

PVSCSI adapters are high-performance storage adapters that can result in greater throughput and lower CPU utilization. PVSCSI adapters are best for environments, especially SAN environments, where hardware or applications drive a very high amount of I/O throughput. The VMware PVSCSI adapter driver is also compatible with the Windows Storport storage driver. PVSCSI adapters are not suitable for DAS environments. VMware Paravirtual SCSI adapters are high-performance storage adapters that can result in greater throughput and lower CPU utilization. [1]

The PVSCSI adapter offers a significant reduction in CPU utilization as well as potentially increased throughput compared to the default virtual storage adapters, and is thus the best choice for environments with very I/O-intensive guest applications. [2]

Changing VMware Storage Controller to Paravirtual for CentOS 7

This tutorial contain step by step guidance to change the Virtual Storage Controller from LSI Logic Parallel (SCSI controller 0) to VMware Paravirtual for a CentOS 7 based Virtual Machine that is running on the ITS Private Cloud.

1. Create a Virtual Machine Snapshot:

vss-cli compute vm set <name-or-vm-id> snapshot mk -d "lsi logic to paravirtual" -l 72

Note

More information Manage virtual machine snapshots.

2. Power Off the virtual machine:

vss-cli compute vm set <vm-name-or-vm-id> state shutdown

3. Add a temporary VMware Paravirtual Controller to the Virtual Machine.

vss-cli compute vm set <vm-name-or-vm-id> controller scsi mk --scsi paravirtual

4. Verify that a new SCSI controller has been created.

vss-cli compute vm get <vm-name-or-vm-id> controller scsi

label                bus_number  type
-----------------  ------------  ----------------------------
SCSI controller 0             0  VirtualLsiLogicSASController
SCSI controller 1             1  ParaVirtualSCSIController

5. Power On the virtual machine.

vss-cli compute vm set <vm-name-or-vm-id> state on

6. Login and promote your account to have root level permission.

7. Rebuild the initial ramdisk image:

mkinitrd -f -v /boot/initramfs-$(uname -r).img $(uname -r)

8. Power Off or shutdown the virtual machine:

vss-cli compute vm set <vm-name-or-vm-id> state shutdown

9. Update scsi controller 0 to type Paravirtual:

vss-cli compute vm set <vm-name-or-vm-id> controller scsi up -t paravirtual 0

10. Check whether the update executed successfully:

vss-cli compute vm get <vm-name-or-vm-id> controller scsi

label              bus_number    type
-----------------  ------------  ----------------------------
SCSI controller 0             0  ParaVirtualSCSIController
SCSI controller 1             1  ParaVirtualSCSIController

11. Remove temporary SCSI controller

vss-cli compute vm set <name-or-vm-id> controller scsi rm 1

12. Power On the virtual machine:

vss-cli compute vm set <vm-name-or-vm-id> state on

13. Verify everything is working well.

14. (Optional) Remove Virtual Machine snapshot:

vss-cli compute vm set <vm-name-or-vm-id> snapshot rm <snap-id>

Note

More information Manage virtual machine snapshots.

Changing VMware Storage Controller to Paravirtual for Windows

This tutorial contain step by step guidance to change the Virtual Storage Controller from LSI Logic SAS (SCSI controller 0) to VMware Paravirtual for a Microsoft Windows Server 2016 or later (64-bit) based Virtual Machine running on the ITS Private Cloud [3].

Warning

Ensure machine is patched and latest VMware Tools installed and running.

If VMware Tools is ever removed from the system, it will not boot.

Note

If the device has more that one controller to start, please do not blindly follow instruction to will need to adjust to your environment and the controller id’s being referenced.

1. Create a Virtual Machine Snapshot:

vss-cli --wait compute vm set <name-or-vm-id> snapshot mk -d "lsi logic to paravirtual" -l 72

Note

More information Manage virtual machine snapshots.

2. Shutdown/Power Off the virtual machine:

vss-cli --wait compute vm set <vm-name-or-vm-id> state -c shutdown

3. Add a temporary VMware Paravirtual Controller to the Virtual Machine.

vss-cli --wait compute vm set <vm-name-or-vm-id> controller scsi mk -s paravirtual

4. Verify that a new SCSI controller has been created.

vss-cli compute vm get <vm-name-or-vm-id> controller scsi

label                bus_number  type
-----------------  ------------  ----------------------------
SCSI controller 0             0  VirtualLsiLogicSASController
SCSI controller 1             1  ParaVirtualSCSIController

5. Power On the virtual machine.

vss-cli --wait compute vm set <vm-name-or-vm-id> state on

6. Log Onto windows machine to verify whether the VMware Paravirtual driver get installed using Device Manager > Controllers > PVSCSI device.

7. Shutdown/Power Off the virtual machine:

vss-cli --wait compute vm set <vm-name-or-vm-id> state shutdown

8. Update scsi controller 0 to type Paravirtual:

vss-cli compute vm set <vm-name-or-vm-id> controller scsi up -t paravirtual 0

9. Check whether the update executed successfully:

vss-cli compute vm get <vm-name-or-vm-id> controller scsi

label              bus_number    type
-----------------  ------------  ----------------------------
SCSI controller 0             0  ParaVirtualSCSIController
SCSI controller 1             1  ParaVirtualSCSIController

10. Power On the virtual machine.

vss-cli --wait compute vm set <vm-name-or-vm-id> state on

11. Log Onto windows machine to verify boot and driver changed, in device manager you will now see 2 - controllers PVSCSI device.

Note

In Multi-disk environment, you will need to check and likely bring the additional disks online using computer manager

12. Shutdown/Power Off the virtual machine:

vss-cli --wait compute vm set <vm-name-or-vm-id> state shutdown

13. Remove temporary SCSI controller

vss-cli --wait compute vm set <name-or-vm-id> controller scsi rm 1

14. Power On the virtual machine.

vss-cli --wait compute vm set <vm-name-or-vm-id> state on

15. Log Onto windows machine verify boot and removal of secondary scsi controller using the device manager.

16. (Optional) Remove Virtual Machine snapshot:

vss-cli --wait compute vm set <vm-name-or-vm-id> snapshot rm <snap-id>

Note

More information Manage virtual machine snapshots.

[1]

VMware KB 1010398

[2]

Performance Best Practices for VMware vSphere 6.7

[3]

Contributed by Joe Bate.