TOPIC: DISK IMAGES
Converting QEMU disk images to VirtualBox images on Linux Mint 21
30th October 2022Recently, VirtualBox gained fuller support for Windows 11 and I successively set up a new Windows 11 virtual machine that, I hope, will supplant a Windows 10 counterpart in time. While the setup itself was streamlined, I ran into such stability issues that I set the new VM aside until a new version of VirtualBox got released. That has happened with the appearance of version 7.0.2, but Windows 11 remains prone to freezing on my Linux Mint machine. Thankfully, that now is much less frequent, yet the need for added stability remains outstanding.
While I was thinking about trying out VirtualBox 7.0.0, I remembered a QEMU machine that I had running Windows 11. Though QEMU proved more limited than VirtualBox when it came to having easy availability of functionality like moving data in and out of the virtual machine or support for sound, there was no problem with TPM support or system stability. Since it did contain some useful data, I wondered about converting its virtual hard disk to VirtualBox format, and it is easy to do. First, you need to install qemu-img and other utilities as follows:
sudo apt-get install qemu-utils
With that in place, executing a command like the following performs the required conversion. Here, the -O switch specifies the required file type of vdi in this case.
qemu-img convert -O vdi [virtual hard disk].qcow2 [virtual hard disk].vdi
While I have yet to mount it on the new VirtualBox Windows 11 virtual machine, it is good to have the old virtual hard disk available for doing so. The thought of using it as a boot drive in VirtualBox did enter my mind, but the required change of drivers and other incompatibilities dissuaded me from doing so.
Changing the UUID of a VirtualBox Virtual Disk Image in Linux
11th July 2021Recent experimentation centring around getting my hands on a test version of Windows 11 had me duplicating virtual machines and virtual disk images, though VirtualBox still is not ready for the next Windows version; it has no TPM capability at the moment. Nevertheless, I was able to get something after a fresh installation that removed whatever files were on the disk image. That meant that I needed to mount the old version to get at those files again.
While renaming partially helped with this, what I really needed to do was change the UUID, so VirtualBox would not report a collision between two disk images with the same UUID. To avoid this, the UUID of one of the disk images had to be changed and a command like the following was used to accomplish this:
VBoxManage internalcommands sethduuid [Virtual Disk Image Name].vdi
Because I was doing this on Linux Mint, I could call VBoxManage without need to tell the system where it was, as would be the case on Windows. Otherwise, it is the sethduuid portion that changes the UUID as required. Another way around this is to clone the VDI file using the following command, but I had not realised that at the time:
VBoxManage clonevdi [old virtual disk image].vdi [new virtual disk image].vdi
It appears that there can be more than one way to do things in VirtualBox at times, so the second way will remain on reference for the future.
Moving a Windows 7 VM from VirtualBox to VMware Player
14th October 2012Seeing how well Windows 8 was running in a VMware Player virtual machine and that was without installing VMware Tools in the guest operating system, I was reminded about how sluggish my Windows 7 VirtualBox VM had become. Therefore, I decided to try a migration of the VM from VirtualBox to VMware. My hope was this: it would be as easy as exporting to an OVA file (File > Export Appliance... in VirtualBox) and importing that into VMware (File > Open a VM in Player). However, even selecting OVF compatibility was insufficient for achieving this, and the size of the virtual disks meant that the export took a while to run as well. The solution was to create a new VM in VirtualBox from the OVA file and use the newly created VMDK files with VMware. That worked successfully to give me a speedier, more responsive Windows 7 VM for my pains.
Access to host directories needed reinstatement using a combination of the VMware Shared Folders feature and updating drive mappings in Windows 7 itself to use what appeared to it as network drives in the Shared Folders directory on the \\vmware-host domain. For that to work, VMware Tools needed to be installed in the guest OS (go to Virtual Machine > Install VMware Tools to make available a virtual CD from which the installation can be done) as I discovered when trying the same thing with my Windows 8 VM, where I dare not instate VMware Tools due to their causing trouble when I last attempted it.
Moving virtual machine software brought about its side effects, though. Software like Windows 7 detects that it's on different hardware, so reactivation can be needed. While Windows 7 reactivation was a painless online affair, it wasn't the same for Photoshop CS5. That meant that I needed help from Adobe's technical support people top get past the number of PC's for which the software already had been activated. In hindsight, deactivation should have been done before the move, but that's a lesson that I know well now. Technical support sorted my predicament politely and efficiently while reinforcing the aforementioned learning point. Moving virtual machine platform is very like moving from one PC to the next, and it hadn't clicked with me quite how real those virtual machines can be when it comes to software licensing.
Apart from that and figuring out how to do it, the move went smoothly. An upgrade to the graphics driver on the host system and getting Windows 7 to recheck the capabilities of the virtual machine even gained me a fuller Aero experience than I had before then. Full screen operation is quite reasonable too (the CTRL + ALT + ENTER activates and deactivates it) and photo editing now feels less boxed in too.
Disk corruption can be virtual too
16th July 2008It's the sort of sight that causes you to fear the worst, an unchanging black screen with a flashing cursor. That was what started to greet me recently when I tried to fire up a Windows XP guest in VMware Workstation. The cause was the corruption of a virtual disk, an ominous thing that affected a supplemental virtual hard drive that I had added to the virtual machine rather than its main one. Though there might have been some data on there, it was nothing that I didn't have elsewhere anyway. Removing the broken disk from the XP VM returned the situation to fuller health, and I simply tried creating a new one again. So far, this seems to be working fine, yet I'll be keeping a watchful eye on things.
So far, I have no idea why the corruption happened, but the broken disk files were created without a VMDK extension, which might indicate that something was amiss with the process that created them. While it would be better if VMware highlighted the state of its virtual disks, it was when I tried opening the trashed disk with VirtualBox that a warning was given and VMware did the same when I tried it with that afterwards (opening VMware virtual disks with VirtualBox is possible, but you need to ensure that no attempt at importation is made, or you could end up with a breakage). While I may have discovered the fault in a roundabout manner, it's better to know what's gone wrong than not to know at all.