I was looking for a way to shrink the size of a virtual disk in Virtual
Server or Virtual
PC and came across a whole bunch of tips
and tricks for Virtual Server at Robert
Moir’s blog. Essentially there are two techniques which should work:
1. Backup any critical data in the guest OS.
2. Download Eraser, (http://www.tolvanen.com/eraser/)
and install it in the guest OS. Alternative disk ‘zeroing’ software can also be used.
3. Defragment the guest OS hard drive.
4. Run Eraser in the guest OS.
5. Click Edit, then Preferences, then Erasing
6. Select Unused Disk Space
7. Select New
8. Enter the description Blank
9. Click Add
10. Create a 3-byte pattern of zeros
11. Click Save
12. Select Blank under Unused disk space
13. Click OK.
14. Click File, then New Task
15. Select Unused space on drive
16. Select Local Hard Drives
17. Click OK
18. Select Task, then Run on the previously created task
19. Wait for completion
20. Close the report
21. Exit Eraser and shutdown the guest PC.
22. Use Virtual Disk Wizard on the Host PC to reclaim lost space. Click File, then
Virtual Disk Wizard.
23. Click Next to start the wizard.
24. Select Examine or modify existing disk and click Next.
25. Click Browse to locate the disk image, double-click the image file and click Next
26. Select Compact the Disk image and click Next.
27. Virtual PC allows the use of a secondary file to compact the disk. It’s a good
idea to have the image file be compacted to a new file and then verified to prevent
data loss or corruption of the original image file. Select New File, browse or enter
a new location, click Next to continue.
28. Click Finish to start the process.
When finished, click Close.
Another method that can work is to use Ghost or
a similar product inside your guest machine to copy your hard drive image to a new
virtual hard drive, and then mount that as your new main hard drive for that virtual
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