VMware Fusion’s Grossly Huge Virtual Disk
Posted by IronMac on December 28th, 2008
Very recently it came to my attention, via Fusion’s warning that it could not do any more backups due to a lack of disk space, that my MBP’s 250 gig hard drive was quickly running out of room. How could this be? I rarely download torrents and I could not see where I could be generating so many files in so short a period. After a bit of searching, along with the use of a program called GrandPerspective, it became clear that it was Fusion that was taking up a huge amount of room to the tune of 58 gigs!
As an aside, GrandPerspective is very easy to use and uses a colour-coded map to show groupings of files and folders and how much space they use.
58 gigs was obviously very shocking since I had thought that I only allocated 40 gigs to Fusion and that it was a hard limit. Good thing I had earlier purchased a Take Control ebook from Tidbits Publishing called Take Control of VMware Fusion 2. It’s an excellent book that’s easy to read with good explanations of what does what and why certain actions should be taken. In it, Kissel talks about how to shrink a virtual disk which is where virtual machines store their data. It turns out that every time I save a file, delete a file, save a game, delete a game, and Fusion does a “snapshot” of itself, the virtual disk grows bigger. Obviously, major shrinkage will have to now occur or else Fusion’s virtual disk will take over the whole system.
So, the steps are:
- (This is recommended) First, go into the WinXP environment and defrag the hard drive.
- Shut down (don’t suspend) the Windows by choosing Virtual Machine -> Shut Down Guest.
- Delete all snapshots by choosing Virtual Machine -> Snapshots and this includes not only the ones done by yourself but by Fusion too. You cannot delete the “running” state snapshot but that’s ok.
- Go to Virtual Machine -> Settings and select Hard Disks.
- Select the hard disk that you want to shrink and click on Clean Up Disk.
Ok, the steps may sound pretty easy but I encountered a couple of problems which are probably my fault. First, the defragging of the hard drive process encountered a problem when Fusion ran a backup. I don’t know what happened but it then could not continue with the defragging process because it could not find a certain file. This became a nightmare of trying to shut down the virtual machine and restarting it and finally I had to use the rollback function to go back to an early snapshot of the system and start again.
I never did do a complete HD defrag as I continued with the deleting snapshot step. Each snapshot can take up to a gig of space and Fusion takes quite a while to first delete and then clean up files. I’ve found that Fusion took a long time with the later snapshots but speeded up quite nicely with the earliest ones. I suspect that this may have to do with the size of the snapshots with the later ones being much larger. In all, this process took about four hours as I periodically came back to the MBP to check.
The last step of shrinking the virtual disk took Fusion about an hour and was a lot simpler. It’s a good idea not to become alarmed if Fusion seems to hang or take a long time doing something. It’s only when you do a Option+Open Apple+Esc and find that it’s no longer responding that it’s time to force-quit Fusion, which I had to do a few times. So, after several hours, Fusion is now 30 gigs smaller in size in a process that Kissel recommends being done every couple of months.
