Automatically Defrag your Citrix PVS vDisks

Here is a script to automate 'offline defragging' your PVS vDisks.  Why Defrag?  It's explained nicely here.

Effects of Fragmentation on Write Cache Size
The culprit above in excessive write cache size is fragmentation. This is caused because PVS redirection is block based and not file based. The redirection to the write cache is based on the logical block level structure of the vDisk. To illustrate this, consider the scenario below.

And the script: