Guest not accessible - VBOX_E_OBJECT_IN_USE

[Nussknacker]

I'm using VirtualBox for years now, current Host is Kubuntu Linux 16.04. There are various guests, including ''Windows XP home SP 2 32bit''.

On February 27th the Muon package management has updated VirtualBox to 5.2.38. On March 2nd I started VirtualBox and installed the current version of the Extension Pack. Then I started the Windows XP VM and updated the guest extension. Afterwards I could work with Windows XP without any problems.

On May 16th the Muon package management has updated VirtualBox to 5.2.42. Today I started VirtualBox and installed the current version of the Extension Pack. Now Windows XP is not accessible. Error message:

Cannot attach medium '/usr/share/virtualbox/VBoxGuestAdditions.iso' {e1eb94c6-7ba3-4847-81fc-2538beb2cce1}: medium is already associated with the current state of machine uuid {5e67f5c1-fe75-4413-958a-b9f587ced97f}!
Error code: VBOX_E_OBJECT_IN_USE (0x80BB000C)
component: MediumWrap
Interface: IMedium {4afe423b-43e0-e9d0-82e8-ceb307940dda}

Refresh changes nothing.

The other guests seems tp work fine.

I'm quite nervous because there is an important application running in the VM. What can I do?

[mpack]

Check if you are able to release and remove that media in the manager: File|Virtual Media Manager....

Something very similar was reported just a few days ago. In that case the user had somehow managed to add multiple DVD drives to the VM, with the same ISO mounted in all of them. Of course in the physical world it would be impossible to have the same CD/DVD mounted in more than one drive. The appropriate cleanup would be to remove the extra drives, then release the media as mentioned.

[Nussknacker]

The appropriate cleanup would be to remove the extra drives, then release the media as mentioned.

"release and remove that media in the manager: File|Virtual Media Manager...."? Can you please give me a step by step guide - or give me a link?

[mpack]

Select the "Optische Medien" (Optical disks) tab, select the appropriate ISO media from the list, then click "Freigeben" (Release) followed by "Entfernen" (Remove).

[Nussknacker]

I assume you mean the GuestAdditions? I can't release or remove this ISO.

But the file is stored, like expected: /usr/share/virtualbox/VBoxGuestAdditions.iso

[mpack]

Ok, so what happened when you turned to the second paragraph of my advice?

[Nussknacker]

Do you mean "The appropriate cleanup would be to remove the extra drives, then release the media as mentioned."?

HowTo? Selecting a working VM > Settings > Storage > selecting IDE Controller VBoxGuestAdditions.iso > Remove selected storage > OK?

And repeating this with every VM? Or just with machine uuid {5e67f5c1-fe75-4413-958a-b9f587ced97f}? But witch one is it?

And afterwards going to Globale Tools > selecting VBoxGuestAdditions.iso > Release > Remove?

Looks al little bit strange to me because I didn't changed the IDE Storage for month/years now. But if you recommend it, I will do it.

[mpack]

You reported a problem with one VM, so why would I tell you to do something to every VM?

If you remove all CD/DVD drives from the VM recipe that should certainly cure the problem of an ISO being mounted there. No need to mess with Virtual Media Manager after that. If you then ONE CD drive back then it should be empty.

[Nussknacker]

You reported a problem with one VM, so why would I tell you to do something to every VM?

OK, sounds logical. But VBoxGuestAdditions.iso is attached to nearly every VM.

If you remove all CD/DVD drives from the VM recipe that should certainly cure the problem of an ISO being mounted there.

But Windows XP > Settings > Storage > selecting IDE Controller VBoxGuestAdditions.iso > Remove selected storage doesn't work because of the error. And Globale Tools > selecting VBoxGuestAdditions.iso > Release > Remove is not selectable.

Unfortunately I need more detailed help.

What do you mean by "VM recipe"?

[mpack]

OK, sounds logical. But VBoxGuestAdditions.iso is attached to nearly every VM.

Perhaps so, but that doesn't mean that every VM has a problem. It would take work to repeat the same error in every VM, so for the moment I'm going to assume otherwise. But FYI for the future: it is bad practice to leave the GAs ISO mounted in the VM, for precisely the reason we're seeing here. Install GAs, eject ISO.

But Windows XP > Settings > Storage > selecting IDE Controller VBoxGuestAdditions.iso > Remove selected storage doesn't work because of the error.

In that case, zip up the ".vbox" file in the VM folder, attach the zip to a message here.

[Nussknacker]

But FYI for the future: it is bad practice to leave the GAs ISO mounted in the VM, for precisely the reason we're seeing here. Install GAs, eject ISO.

Thanks. I will bear that in mind for the future.

In that case, zip up the ".vbox" file in the VM folder, attach the zip to a message here.

Done. I appreciate your patient helpfulness.

[mpack]

Wow, it looks like you were really determined to destroy this VM.

First of all, you had four different DVD drives attached to the VM. You really need to learn the distinction between inserting DVD media into a PC, and installing a new DVD drive in a PC - it's a pretty crucial difference! Weirdly it looks like you added a superfluous SATA controller to this VM (XP has no native support for SATA), just so you could add a new DVD drive after maxing out the 4-drive limit for IDE (1 hdd + 3 dvd).

XP wouldn't see any SATA drive without third party drivers, but VirtualBox would! And I guess that VirtualBox might well insert the GAs CD into that inaccessible drive if it was the last one added. I must say that AFAIK this is a refreshingly new and original way to mess XP/VirtualBox up.

To compound your problems you are also using snapshots, so every snapshot had its own record of the what is in each of the DVD drives, which greatly complicates fixing the problem. Most experienced users no long use snapshots - if you want to preserve a VM state it's better to make a proper backup of the VM folder.

[Nussknacker]

Thanks for fixing the VM for me! That's very nice!

Wow, it looks like you were really determined to destroy this VM.

I admit: I installed VirtualBox in 2010 and setted up the VMs. Since then I have only worked in the VMs. Whatever additional DVD or IDE / SATA drives were attached, it was not a conscious intention on my part.

Weirdly it looks like you added a superfluous SATA controller to this VM (XP has no native support for SATA), just so you could add a new DVD drive after maxing out the 4-drive limit for IDE (1 hdd + 3 dvd).

XP wouldn't see any SATA drive without third party drivers, but VirtualBox would! And I guess that VirtualBox might well insert the GAs CD into that inaccessible drive if it was the last one added.

Currently all VMs are running. But how do I prevent these problems in the future?

Machine > Settings > Mass Storage > Controller IDE should contain a DVD for the Guest Additions?
Machine > Settings > Mass Storage > Controller SATA should contain a *.vdi / *.vmdk disc image?

This seems to be true for all VMs. I just checked it.

To compound your problems you are also using snapshots, so every snapshot had its own record of the what is in each of the DVD drives, which greatly complicates fixing the problem. Most experienced users no long use snapshots - if you want to preserve a VM state it's better to make a proper backup of the VM folder.

I didn't know that. That's too bad, because some VMs contain many snapshots. How can I get rid of them without any problems?

In which order should I delete the snapshots?

Or should I select a snapshot and then export this version? With Appliance export as *.ova? (I think, that's what you call a backup?)

Do the snapshots remain if I copy a disk image with Global Tools?

[mpack]

But how do I prevent these problems in the future?

As I already said: learn the difference between adding a new drive and adding media to an existing drive.

You don't need to export to get rid of snapshots. Simply cloning the VM (current state only) will do the job. Or, just delete the snapshots - order doesn't matter - after making a backup of the VM folder.

[Nussknacker]

You don't need to export to get rid of snapshots. Simply cloning the VM (current state only) will do the job. Or, just delete the snapshots - order doesn't matter - after making a backup of the VM folder.

At the risk of upsetting you, I have to ask again:

By cloning you mean Machine > Cloning? This will change the UUIDs and MAC addresses, which can be a problem if the Windows-guest is activated, right?

By (unnecessary) export you mean File > Appliance export? Does this change the UUIDs and MAC addresses too?

With backup you mean to copy the complete folder in the file manager? This does not changes the UUIDs and MAC addresses. But I have learned that this can cause problems. Or do I just have to do not to use the original and the copy at the same time? Do I just have it un-/registered with VirtualBox by using Machine > Remove / Add to avoid these problems?