virtualbox.org

I had a really long session with VirtualBox, opening/closing VMs for several days. I got a hold of 10.10.1 and decided to give it a try. I set up a new VM, with the exact same settings as my existing 10.10. A couple of reboots here and there and after the basic installation, I chose Create Snapshot ('Basic'). Do some more testing, decide to revert. And, here we go...

I tried to revert to 'Basic'. VBox says that the current stage is still changed. Boot the VM, close it and choose to revert. Still, current state shows as changed. Close VBoxManager, restart. Try to revert. Reboot. Revert. Nothing. Close VBoxManager, relaunch. Big surprise, all the fields in the VM are empty and inaccessible!!! What??? Time to hit the tools.

Close VBoxManager. Open '10.10.vbox' and '10.10.1.vbox' in a text-comparing editor (remember, they were almost identical). Compare the two and below is the "corruption":

10.10   : <AttachedDevice type="HardDisk" ...
10.10.1 : <AttachedDevice type="HardDisk" hotpluggable="true" ...
10.10   : <AttachedDevice passthrough="false" type="DVD" ...
10.10.1 : <AttachedDevice passthrough="false" type="DVD" hotpluggable="true" ...

Removing the hotpluggable="true" from the '10.10.1.vbox' fixed the VM. Now, as far as I know there is no way to set a HD/DVD as hotpluggable from the UI and even in the VBoxManage commands, I couldn't find anything relevant. The only brief mention is something in Chapter 9.24 and some mentions in several older release notes.

I'm not sure what happened here, but I'm just posting it so that if someone that stumbles upon it in the future, the search engines will pick it up. Of course I definitely wouldn't mind an actual explanation from anyone...

I tried reproducing what you found.

Started 10.10.1, created a snapshot, installed some software, shut the guest down, restored the snapshot, restarted the guest. Every thing was fine and my .vbox file still said…

<AttachedDevice passthrough="false" type="DVD" port="1" device="0"/>

The only difference that is obvious between yours and mine is, when I installed 10.10.1, I just installed it over my 10.10 install. So mine says OSX 10.10.vbox and not OSX 10.10.1.vbox.

btw: the iMac I'm using has no internal or external CD/DVD drive.

Actually I stole the idea to do a fresh installation from you from another thread where there was a comparison between an upgrade from 10.10 and a straight installation of 10.10.1

But no, it's not reproducible, it was just ... weird. That's why I mentioned that it was a several days streak that VBox was running. Something got confused over there? I mean, I've searched to find the steps to enable hotplugging of a HD and I couldn't. And VBox decided to do it on its own???

Well, I can't say I know what's up. As you know trying to get OSX guests working correctly is problematic so who knows. Plus OSX 10.10.1 still has a few bugs.

edit: I don't know with any certainty VB 4.3.18 is 100% compatible with OSX 10.10 or 10.10.1 on the host either.