|
Patch reliability is unclear. Unless you have an immediate, pressing need to install a specific patch, don't do it. |
I have a Windows (2000) VM in VirtualBox with a dynamic expanding drive. I need to shrink the drive size since I’ve removed a couple GB of files from the VM. How would I go about doing that? Does it require zeroing out the data on the Windows side then finding a way to adjust the VM hard drive size?
Thanks!
Nathan Parker
It’s done in the VM manager with the client shut down – assuming it is possible in your software.
Alternatively you could create a new disk, connect it to the VM, boot the whole lot with a backup/clone utility and clone. Then disconnect the old disk and connect the new one in the same location. If all is well, delete the old disk.
cheers, Paul
In the VirtualBox program directory is a command-line utility called vboxmanage.exe that is supposed to do this with the command “vboxmanage modifyhd –compact”.
That said, I’ve never had much luck getting it to compact very much, so I usually resort to Paul’s second suggestion: create a new (dynamically expanding) virtual disk, attach it to the VM, boot the VM from a cloning program’s boot disk (example: an ISO of a Macrium Reflect “Rescue CD”), and clone the original disk to the new disk. That does a really good job of shrinking a virtual disk file.
To shrink the virtual disk file, free space has to be zeroed first. Within a Windows guest, it is generally suggested to do that with SDelete.
I usually run SDelete after clearing app caches and getting rid of other temporary files with the built-in Disk Cleanup utility. Then I shut down the VM and run the “compact” command.
From the online manual: 8.22. VBoxManage modifymedium (modifyhd is still supported).
Within a Windows guest, it is generally suggested to do that with SDelete. I usually run SDelete after clearing app caches and getting rid of other temporary files with the built-in Disk Cleanup utility. Then I shut down the VM and run the “compact” command.
I did not know about the sdelete utility. I tested it on a copy of a vdi file and it worked great!
sdelete is the standard and most well-known way to resolve this issue.
An alternative way built in the OS utility defrag is to run:
defrag -C -L -H
or the equivalent explicit
defrag /AllVolumes /Retrim /NormalPriority
For more information and suitable switches, try from a command line run as administrator:
defrag /?
Having issues running sdelete on Windows 2000. I keep receiving an error message saying not a valid Win 32 application.
Nathan Parker
Sorry! It seems I didn’t pay attention to the SDelete documentation I linked to, and failed to notice it is for Vista and above.
A bit of research suggests that in Windows 2000, perhaps the same job can be done with the built-in command line tool called cipher. For example, use cipher /w:C to wipe the free space on drive C.
Sorry! It seems I didn’t pay attention to the SDelete documentation I linked to, and failed to notice it is for Vista and above.
I guess I also missed that.
In my experiment, I had disconnected the vdi file from the Win2K VM and connected it as a secondary to a Win7 VM, and ran the sdelete utility from Win7.
I did that merely because I already had the sdelete utility downloaded to the Win7 VM, so it was quicker for me to move the vdi disk rather than booting the W2K VM and re-downloading the sdelete utility.
So I guess I accidentally avoided the W2K incompatibility without knowing it.
SDelete is only a data overwrite utility. It doesn’t free up space.
I can’t see how that will affect a VM as the VM doesn’t track free/unused space, that’s done by the client OS and the VM expands the disk as the OS requests more file space.
cheers, Paul
Right. Once SDelete (or similar utility) has been used within the guest (client) to zero the free space created by deleting files, the VM manager’s compact utility will be able to do a nice job of shrinking the virtual disk file.
As an example, this morning I ran through the process of updating my Windows 8.1 Pro guest with the April patches, then performing a Disk Cleanup and SDelete, and then compacting the VDI.
Before starting up the guest:
After running Windows Update, Disk Cleanup, SDelete, and shutting down the guest:
After running VBoxManage modifymedium –compact ‘Windows 8.1 Pro.vdi’:
Tried Cipher and the Compact, and it seems the reverse happened. It expanded the disk to its full size.
Should I try cloning the drive to another dynamic expanding drive now? 
Thanks!
Nathan Parker
Or! Find an older version of SDelete compatible with Windows 2000. 
A walk through the Wayback Machine showed me that sometimes Microsoft upped the minimum supported version of Windows without actually updating SDelete!
So, here’s a couple of links for ya:
I suspect, but have not been able to verify (due to no handy copies of these older Windows versions) that SDelete 2.0 is the one that actually dropped support for pre-Vista versions.
Should I try cloning the drive to another dynamic expanding drive now?
That’s what I would do. But don’t use the vboxmanage.exe utility to clone/copy from outside the VM — I think vboxmanage.exe just duplicates the vdi file (with a new GUID), so you’d end up with another full-size duplicate.
Go back to the second option Paul and I mentioned in the 2nd and 3rd posts: create/attach a new, dynamically expanding disk, then boot the VM and clone from inside the VM — for instance, by booting the VM from an ISO of a bootable Macrium “Rescue” CD, or similar.
Depending on your choice of program, it might also work by installing the program in your W2K VM, but just to avoid any potential further conflicts, I’d instead create a bootable ISO (from another VM or a real machine) and clone from that environment instead of from W2K.
It expanded the disk to its full size
This is probably because it zeroed free space instead of reading the FAT for unused file locations and only zeroing them.
cheers, Paul
this morning I ran through the process of updating my Windows 8.1 Pro guest with the April patches, then performing a Disk Cleanup and SDelete, and then compacting the VDI.
Please do the testing for us.
cheers, Paul
I’m sorry, but I won’t be going that far. I’ve done my best to help the OP with the specific situation of needing to compact a Windows 2000 virtual disk in VirtualBox. If I hadn’t already had a VirtualBox-based VM, I wouldn’t have created one just for testing.
If you’re curious to find out which of the two methods will save more space, you may compare them yourself. For my own use, I’m very happy with the results.
I honestly didn’t expect a reduction of over 4GB, as the Disk Cleanup step had only removed 962MB. But then again, that was also the very first time that VDI had been compacted.
Regardless of method used, I hope Nathan achieves success with shrinking the Windows 2000 VM.
Sounds good. I’ll do the test with the SDelete versions posted. If I still have issues, I’ll do the clone.
So I’ll do tests until something works, then report back.
Nathan Parker
You need any of the usual backup utilities (EaseUs ToDo, Aomei etc) then create a recovery ISO from that. The ISO is around 500MB.
Clonezilla is an open source alternative with a live CD download – probably easiest.
cheers, Paul
I tried to clone it through CloneZilla, and I also learned that multitasking isn’t a good idea. I ended up messing something up and wiping out my Windows 2000 virtual hard drive. My backup didn’t work either due to the backup issues I’ve had with my NAS.
The good news is I didn’t have much configured on it, and I had the installers for what I put on it (I didn’t have much time to configure it after setting it up), so it was pretty painless to nuke the virtual drives completely and put a fresh copy of Windows 2000 on a fresh virtual hard drive, then reinstall my programs. I’ve successfully backed that copy up now in case something else occurs, so I should be set.
I’ve been knee-deep with my network transition, and trying to work this in while multitasking wasn’t the best move. I should have waited until I could focus on it, but at least the final restore wasn’t too painful.
Nathan Parker
Donations from Plus members keep this site going. You can identify the people who support AskWoody by the Plus badge on their avatars.
AskWoody Plus members not only get access to all of the contents of this site -- including Susan Bradley's frequently updated Patch Watch listing -- they also receive weekly AskWoody Plus Newsletters (formerly Windows Secrets Newsletter) and AskWoody Plus Alerts, emails when there are important breaking developments.
Notifications
