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recovering host disk space after VM removal

Posted: 19. Oct 2015, 02:57
by rossepeo
I am running Win 7 as a guest on my Macbook Pro running OSX 10.7. I removed a VM that had a dynamic disk space of 27Gb. With Win 7 OS and installed apps, used disk space was about 20Gb. Yet after I performed VM removal from within VirtualBox, I only recoverd about 6 Gb (according to my Mac's Finder window). How do I get back the rest of the disk space that is no longer being used by the VM?

Re: recovering host disk space after VM removal

Posted: 19. Oct 2015, 05:18
by BillG
Empty the trash?

Re: recovering host disk space after VM removal

Posted: 19. Oct 2015, 11:35
by mpack
I'm not a Mac user, but doesn't OS X also have some sort of rolling backup feature... is it called Time Machine? ... which stores copies of files (I assume as difference information. This obviously can take up a huge chunk of space if the files have been changing a lot.

Either way - the OP is asking for OS X tuition, which is not really the purpose of these forums.

Re: recovering host disk space after VM removal

Posted: 20. Oct 2015, 21:12
by rossepeo
Since doing a "Remove" of an existing VM resulted in so little disk space recovery, I was thinking maybe there was some additional task that had to be performed from within VirtualBox to "release" the disk space that had been reserved for that VM. From your posted comments, I gather that simply doing a "Remove" for a VM is all that is required for VirtualBox to release that disk space back to the host. If that is indeed the case, then I will delve into the Mac forums to see if others have experienced this low disk space recovery rate. Thanks.

Re: recovering host disk space after VM removal

Posted: 20. Oct 2015, 21:21
by loukingjr
Try turning off time Machine temporarily. If you have Time Machine enabled but it can't connect to the backup drive, it will create a temp backup on the host until such time as it can reach the backup drive. You may have to restart your Mac but I think the space should be released immediately.

Re: recovering host disk space after VM removal

Posted: 20. Oct 2015, 22:42
by mpack
rossepeo wrote:I gather that simply doing a "Remove" for a VM is all that is required for VirtualBox to release that disk space back to the host
VirtualBox does not reserve host disk space. All VirtualBox does to your host is create some files, just like any other host app, and there is nothing unusual about them other than being unusually large. You get rid of them in the normal way.

But no, all that "Remove" does is unregister the media or the the VM. You are then asked if you also want to delete the physical files, the consequence of either answer will be obvious.