Guide to Optimising VDI and RDSH templates on VMware with vWorkspace

Guide to Optimising VDI and RDSH templates on VMware with vWorkspace

Guide to Optimising VDI and RDSH templates on VMware with vWorkspace

                                          Using SESparse disks with vWorkspace to avoid misaligned data

                                                                                                      Andrew Wood Dell Software Group




It is well documented that the older style vmfssparse disk format can cause misaligned data.  This is due to the Grain size of 512bytes

Vmware vSphere 5.1   introduces a new disk format to combat this issue. SESparse disks can be used with Linked Clones so that you do not get the misaligned data.

"... benefits from the new 4KB grain size, which improves performance by addressing alignment issues experienced in some storage arrays with the 512-byte grain size used in linked clones based on the vmfsSparse (redo log) format. The SE sparse disk format also provides far better space efficiency to desktops deployed on this virtual disk format, especially with its ability to reclaim stranded space."

This means that there should be less IO required and the result should be a faster experience for all.

Integration with vWorkspace:

Despite VMware claiming this feature only exists in View, vWorkspace 8.x Supports vSphere 5.1. and when creating a Linked Clone using vWorkspace, it will always use the same Disk Format as the parent VM.

This means that vWorkspace can also use the new format.

However, vSphere 5.1 hides the disk format so it is not selectable within the GUI.

This blog will show you the steps required to create a new Parent VM with the  new disk format.


Creating a SESparse Parent VM:


1. Log into your ESXi Shell


2.Navigate the shell to your Datastore


cd vmfs

cd volumes

cd yourdatastore

3.Create a new folder to store your new vm disk


mkdir xpsparse

cd xpsparse



4. Create a new VMDK with the new SE Sparse disk format by running the following command (20GB disk in this example):

vmkfstools -c 20g -d sesparse WindowsXP.vmdk

5. In order to use the new style disk, you need to use the vSphere Web Client. The old thick vSphere Client does not understand the disk format.


6. Create a new machine and set the compatibility to ESX 5.1 and later


7. On the Customize hardware screen, remove the “New Hard Disk” - we won't be using it.


8. Add the Existing Hard Disk that we created in step 4


9. Do not worry that the disk size says 1MB this is only a display issue in VMware



10.Create your template as normal and then take a snapshot


11. Now, switch to the vWorkspace Management Console


12. In the Add Computer wizard, Import the new Parent VM


13. Select the new snapshot and complete the add computer wizard as normal


14. Once the clone has completed, you can check the Linked Clone's vmdk is the new SESparse format. Use your favourite text viewer.



Andrew Wood

  • Very good work, nicely explained

  • Hi Andrew, anything similar things for vWorkspace and MS Hyper-v ? Thanks...