More often than not, storage design considerations are NOT taking into account when users start rolling out VMware View environments. This can lead to unexpected performance issues, particularly when using linked clones. Using linked clones on an array with SATA drives and very little cache is just asking for trouble however there is a way out: Converting those linked clone desktops to fully deployed or thick disk desktops. This will spread the I/O over more spindles instead of concentrating all requests to one particularly spindle.
There are two ways to do this:
1. Hot/cold clone the desktop VM:
This clone operation can be done with the desktop power on or off, doesn’t matter. This operation will read the linked clone, which is essentially a snapshot file, and follow the chain all the way down to the base image in order to create a stand-alone disk(s) that are independent of the linked clone infrastructure.
From vCenter, right click on the desktop VM and select “Clone”. Simply follow the wizard to clone the virtual machine. When it comes time to selecting what to do with the disk, select “Same format as source”. While this sounds like the opposite of what you would want to do because it is a linked clone, it still sees the linked clone merely as a snapshot. Cloning from the last snapshot of a vmdk file will include all of the changes down to the base disk. This operation will create a brand new, thick vmdk file for each disk for that VM.
The benefit of this method is that cloning or copying the VM allows for verification that the process has completed successfully before removing the linked clone VM in View Manager and manually adding this new one.
2. Storage VMotion the desktop VM:
Using Storage VMotion will convert the VM in the same way as hot/cold cloning with the exception that this can be done with no downtime for the desktop.
From vCenter, right click on the desktop VM and select “Migrate”. Next you will need to select “Change datastore”. Follow the steps that follow and ensure that you select “Same format as source” under the disk section. This will initiate the same consolidation process as mentioned in hot/cold cloning.
The benefit of this operation is the lack of downtime. The downside to this operation is the lack of verification process as well as the need for free disk space to be available on another datastore.