How to Reduce the Allocated Size of a Thin Provisioned VMDK

[GCurtisECHN]

I want to reduce the amount of allocated space to a Windows Server 2008 VM from 400 GB to 250 GB. I already used SVmotion to free up the space, and shrunk the disk in Windows. Now, though, I need to reduce what's allocated to it so I can avoid being over-allocated (test boxes are tending to actually fill their disks with backup files, and since they're over-allocated, we're crashing servers). I simply don't know how to complete the task without losing the data and really appreciate anyone's help.

[vmroyale]

Hello and welcome to the forums.

The easiest way to do this is to use VMware Converter. This will allow you to resize the VMDK as part of the process.

Good Luck!

[GCurtisECHN]

Thanks. Since I've never used that before, however, a few pointers would be welcome, too. :smileyconfused: I may be oeverthinking it prior to actually reading some Converter documentation, but I'm worried about what happens from the Windows Server when suddenly it's not seeing the same size volume.

[vmroyale · Accepted solution]

The Converter will take care of making Windows happy, to grossly oversimplify it.

The nic will change, and the server will get a new MAC Address and will have to be re-IP addressed as well. Other than that the process is fairly straightforward and Windows won't be missing anything. The true beauty of it is that you have the source VM still available, so if anything goes wrong there is an instant failback.

[GCurtisECHN]

Cool. Thank you very much for replying so quickly.