Many of you will be aware of VMware’s recent introduction of the SE Sparse Disk. This is VMware’s first effort to allow you to reclaim dead space from within the Guest OS. Right now, it is only supported with VMware Horizon View version 5.2, so basically is limited to View desktops. For general purpose virtual machines, we still do not have a solution.
We had some workarounds in the past – notably running SDelete to do a zero fill operation within the (Windows) Guest OS, and then migrate the VM between datastores of differing block sizes. Well, that method was lost with the introduction of a unified 1MB file block size with VMFS-5. So I was very interested when Bob reached out about their new PerfectStorage solution for reclaiming dead space within a Guest OS.
In Bob’s own words: “PerfectStorage includes an enterprise console that allows the product to be deployed, installed and scheduled across the physical and virtual servers in the enterprise. PerfectStorage can be scheduled to run unattended, on multiple systems at the convenience of the system/storage administrator and there is no need to shut down system activity. The product can perform an analysis of each thin-provisioned volume and provide an estimate of how much space can be reclaimed. The SMART Zero-Fill feature will only write zeros to those clusters that are not already zeroed. Administrators opt for the type of reclamation they want to do and PerfectStorage performs the Zero-Fill or issues the UNMAP command for the reclaimable space.
PerfectStorage will do Zero-Fill on any storage controller that has zero detection capability for Windows Vista and above and Windows 2003 SP1 and above. To perform the UNMAP function requires VMware 5.1 and Virtual Hardware 9 on the Windows guests or Hyper-V 2008/R2 or 2012″
PerfectStorage product trials are now available at http://download.raxco.com/perfectstorage. The link has two places where it asks “Find Out if PerfectStorage is Right For You”. Based on some questions that arose during early beta, Raxco put together a short decision tree that lets an administrator know if PerfectStorage will work for them.
Seems like this could be a nice tool, and I know this is an area of pain for many administrators. Worth checking out in my opinion.