"Allocated disk size" has nuances when dealing with virtualized disks (especially when you define virtual disks that aren't fully allocated at creation time). The XP environment sees a virtual di...
See more...
"Allocated disk size" has nuances when dealing with virtualized disks (especially when you define virtual disks that aren't fully allocated at creation time). The XP environment sees a virtual disk of the size that you created. From the Mac side, there's a relationship between the used space reported by XP and the size of the .vmdk files in the virtual machine bundle - but not a strict correspondence. The size on the Mac side will be at least the amount reported by windows, and perhaps more depending how XP has allocated disk space and how you've defined the virtual disk. Also, as etung has noted, snapshots can increase Mac disk usage up to 2x the max size of the virtual disk. That being said, it's important to be precise about where the disk is being reported as being used. Are you saying that the XP installation is running out of space? When you say 1.3 gigs and 3.7 gigs are being used, which OS is reporting that? XP or Mac? Is there a snapshot active (the Fusion GUI will tell you this)? Which OS said it was using 30 GB or 10GB? IIf space is being "hogged" from within the XP guest, then you should be scrutinizing the use of the disk from the XP standpoint. it's not uncommon for a XP guest to use more space when applying Microsoft updates. XP updates not only get loaded down to your system (depending on Automatic Updates preferences), but their installation saves away copies of files they're replacing so they can be backed out. I've also seen updates that you don't want to apply (IE7 comes to mind) sitting in XP because they got downloaded by Automatic Updates. You also have the virtual memory file within XP (page file) that can expand automatically (up to the limits that are configured). Do you have any other software beside the OS installed in your XP guest, such as AV or utilities? Automatic defrag utilities could cause excessive allocation on the Mac side for expandable disks, as they have to move data around on to what they think is unused disk space to do their work. When a disk is allocated sparsely, the "unused" space isn't really there on the Mac's disk - Fusion will have to add it to the virtual disk when the XP guest wants to use it. Using a snapshot does not double the disk requirement - it can take up to 2x the space (an important distinction) depending on activity on the virtual disk and the way the virtual disk was created. What the snapshot does is freeze the original disk. As changes are made, changes get recorded in the files that represent the snapshot. So the size taken up by the checkpoint is proportional to changes that occur since the snapshot was taken. If you take a snapshot and you don't change much, you don't use much extra disk space. Change everything on the XP disk, and you use closer to 2x the disk space that you would normally use. You don't want to disable the use of snapshots (they're very useful when you want to roll back changes you've made to a VM - like protecting yourself against problems encountered when you do a software upgrade). I disagree that it's a prescription for disaster. As with any feature, use it judiciously. I would not have a snapshot active all the time, just turn it on when you need it, and remove it when done. Message was edited by: Technogeezer: Added commentary on snapshot disk utilization