Finding missing drive space on Hyper-V Vm’s with SpaceSniffer

This post was written by the amazing Louis on our team.  He identified a problem where virtual machines would indicate no remaining space and yet show hidden files, etc. turned on, we couldn’t find the culprits.  Stranger still, if we rebooted the space was freed (but I don’t want to be a pirate … I mean, I don’t want to reboot all the time).

Here’s Louis post…

I have been having some odd issues with Hyper-V VM’s reporting inconsistent drive space with large chucks of used data missing. The drive will say its full yet if in windows you select all the data and do an Alt-Enter it shows that the data used doesn’t match how full the drive says it is.

I haven’t found any real solutions from Microsoft, but my fix has been to run a third party program SpaceSniffer. It’s a free executable that give you a nice graphical representation of where all your data is.


Get SpaceSniffer

In this case I found over 60GB of temp data under the c:usersuserxxxAppDataLocalTemp folder that didn’t show in windows even though I had all the hidden file views turned on.