Comments on: Cloning VM’s with VirtualBox, LVM and Snapshots!

By: Ross

Ross — Sun, 10 Apr 2011 01:31:18 +0000

Does it have permission to access that raw device from the user you are running it as?

By: lallau

lallau — Fri, 18 Mar 2011 10:15:10 +0000

Hi, I have been trying to create a rawdisk on a LVM partition.
However, I had the following error :

$ VBoxManage internalcommands createrawvmdk -filename ~/.VirtualBox/VM_1.vmdk -rawdisk /dev/mapper/vg-VM_1
VBoxManage: error: Cannot open the raw disk ‘/dev/mapper/vg-VM_1′: VERR_ACCESS_DENIED
VBoxManage: error: The raw disk vmdk file was not created

The command succeeds if I use sudo but the resulting vmdk file belongs to root.
After some ‘chown’ magic, VirtualBox failed adding this new disk.

Failed to open the hard disk /home/bertrand/.VirtualBox/VM_1.vmdk.
The medium ‘~/.VirtualBox/VM_1.vmdk’ can’t be used as the requested device type.
Result Code:
NS_ERROR_FAILURE (0×80004005)

Any idea ?

By: Ross

Ross — Fri, 03 Sep 2010 00:30:03 +0000

I should note that you can do this from within VirtualBox with a bit of fiddling around using an immutable disk and then creating VM’s from this and telling those differencing disks not to reset.

By: Ross

Ross — Mon, 14 Jun 2010 12:46:58 +0000

No this is completely independent. It would be nice if it did but then it would be less cross platform

By: Chris

Chris — Fri, 23 Apr 2010 20:00:31 +0000

Interesting article. Does VirtualBox support VM snapshots when using an LVM storage backend? i.e. if you click the snapshot button in the GUI will it actually work and generate an LVM snapshot along with the memory snapshot?

By: Ross

Ross — Sat, 23 Jan 2010 10:58:40 +0000

Whilst it is a fast way of getting VM’s up and running it does rely on you keeping an eye on things so that your VM doesn’t grow past the maximum space allocated for changes. So for short term testing its fine.

For more long term fun I’ve been testing lessFS which does data de-duplication. So using the standard VirtualBox interface and VDI files and letting the filesystem do dedupe to save on space. Whilst not “quite” the same speed for building new VM’s its a little nicer for long term VM storage. And the dedupe massively saves on disk if your VM’s are similar operating systems.

By: Alexandre Dumont

Alexandre Dumont — Tue, 19 May 2009 13:36:20 +0000

I’ve just read this post, and although I have tryed it yet, I find it a really nice way of cloning VBox machines. No doubt it’s also the fastest way of doing it.

I’m also using VBox at home, on 2 boxes, one geing Vista, the other Opensolaris 2008.11 (hence why I choose VBox over VMware, for interoperability between those OSes). In none of them I’ll be able to do LVM snapshots, for obvious reason (no LVM support under Vista yet, neither in Opensolaris), but I think the same idea may probably be working with ZFS volumes and snapshots.
I’ll try when time allows me to…

Thanks for sharing the idea!