How to use VMWare "linked clone" in VirtualBox?

[HailThePenguin]

I have two VM's created with VMWare Workstation, and I was able to use them with VirtualBox 4.0.4 on Ubuntu 11.04 very easily. I created new VM's in VirtualBox and made them use the existing VMDK file, and everything worked great. Now I was given a "linked clone" VM created by VMWare Workstation, but I can't figure out how to use it with VirtualBox. There are multiple VMDK files and I tried the same approach with each one, but I never get a bootable VM. Is it possible to do this?

(FWIW, using VMWare Workstation on my system doesn't seem to be an option - I've installed it successfully, but it hangs and crashes every time I start the VM. Completely unusable.)

Thanks!

[mpack]

You don't say if you have the parent VM for the linked clone. If not, then you can't use it.

Even if you do have both parent and child VMs, I think its unlikely you'll be able to use them. VirtualBox is not VMware, it can't use VMware control information directly, you have to build new VMs arounding existing VMDKs, or use the export/import feature. Otherwise you would have to contruct the xml control info manually, and that's a big ask.

Far easier to export from VMware in a form that can be used without the hassle. Personally I would run Disk2VHD inside the source VM, writing the VHD to a USB drive. Then later use CloneVDI to convert VHD to VDI for use in VirtualBox (VirtualBox supports VHD, but VDI is preferred IMHO).

Edit:  Fixed an annoying typo.

[Technologov]

1. You can import/export VMs between vendors using 'OVF' format. (this is not guaranteed to work, but it could)

2. What if you import VMs directly into 4.0.x and then upg. to 4.1.x ? Does it work ?
2.a. If you can provide such a reproducible testcase, it would be great !

[mpack]

AFAIK, exporting from VMWare would flatten the hard disks - it would no longer be a linked clone. If that's acceptable then IMHO simply copying a deliberately flattened VMDK would be easier.

[Technologov]

Ofc. it would...
No way to import/export VMs with linked clones between different hypervisors.

[HailThePenguin]

Maintaining the linked clone and existing snapshots aren't essential in my case. I exported a flattened clone from VMWare and created a new VM using the flattened VMDK in VirtualBox. Unfortunately, the resulting virtual drive appears to be fixed-size, not dynamic; the guest OS (Windows XP) says it's running out of disk space and won't let me install anything due to insufficient space. Is there a way to change the disk to be dynamic?

[mpack]

This is not something I've tried myself, but: go into Virtual Media Manager, highlight the VMDK and select copy. Choose VDI as output format. Hopefully the result will be dynamic. If not then you can use the "VBoxManage clonehd" command instead, as that definitely gives you more control over output formats.

You could also download the CloneVDI tool from the sticky in the "Windows Hosts" forum. It's a Windows app, so you would need Wine to run it on an Ubuntu host. Or another PC running Windows of course. CloneVDI can convert VMDK to VDI, and only ever outputs dynamic VDI. CloneVDI would be a friendlier option than VBoxManage.

[HailThePenguin]

Thanks for the suggestions. I didn't see a Copy option in Virtual Media Manager, only Remove, Release, and Refresh. I tried using "VBoxManage clonehd --format VDI --variant Standard" and the guest OS still thinks it's out of space after I swapped out the VMDK for the VDI.

Running CloneVDI with the compact option in Wine successfully cloned the VMDK to a VDI, but strangely, the guest OS still thinks it's out of space after swapping disks. For what it's worth, Virtual Media Manager reports the VDI is is 20GB virtual and 19.93GB actual. Maybe I'm wrong and the disk isn't actually fixed, but just didn't resize for some reason?

[mpack]

I didn't see a Copy option in Virtual Media Manager, only Remove, Release, and Refresh.

Ah - sorry about that. Although I knew you were discussing a VMware linked clone, mention of "linked clone" still somehow made me have VirtualBox 4.1.0 in mind, as that is when VBox introduced that feature. The "Copy" command in media manager is a VBox 4.1.0 feature.

For what it's worth, Virtual Media Manager reports the VDI is is 20GB virtual and 19.93GB actual. Maybe I'm wrong and the disk isn't actually fixed, but just didn't resize for some reason?

It sounds like the disk is full, and with real data (not deleted files) if CloneVDI with compact didn't shrink it. Resize? You didn't mention attempting to resize the drive? Making the drive dynamic does not allow it to have variable capacity, if that is what you were thinking. The difference between dynamic and fixed drives is described in the user manual, section 5.2.

If you want to enlarge the drive then run CloneVDI again. You will see that it has a drive enlargement feature. Note that you must enlarge both the drive and the guest filesystem on the drive (a.k.a. "partition"). CloneVDI can enlarge any drive. It has a separate option for partition enlargement, however that only works on NTFS and FAT guest filesystems, which is fine if your guest is XP. For EXTx/Linux and other filesystems you would have to use a third party partition manager inside the guest, e.g. by booting from the gparted live CD iso.

[HailThePenguin]

Making the drive dynamic does not allow it to have variable capacity, if that is what you were thinking. The difference between dynamic and fixed drives is described in the user manual, section 5.2.

Yep, I see now I had that wrong.

CloneVDI allowed me to enlarge the drive and partition and everything is working now. Thanks for the help, and great job writing CloneVDI!

[mpack]

You're welcome. You might want to take time to go through the drive to find out what the big space hogging files are. It's possible that you can delete them and then use CloneVDI+compact to shrink the vdi, recovering space on the host drive.

I would strongly advise making a backup of the VDI before you start, just in case you delete something important!

Candidates for deletion include big software patches (including from Windows update) that have already been applied, etc. There are sites which give advice on this.