virtualbox.org

hi,

Up until two hours ago I had a perfectly functional Linux virtual machine. Now I can't get it to start anymore. When I try to I get:

Failed to open a session for the virtual machine Xubuntu.

No error info.

Result Code: E_FAIL (0x80004005)
Component: ProgressProxy
Interface: IProgress {c20238e4-3221-4d3f-8891-81ce92d9f913}

My host is 64bit Windows 8. The machine is Xubuntu. I'm running VirtualBox 4.3.12. Any ideas on how to fix this?

I think it might have something to do with a Windows Update, but since the problem started before I restarted my computer I'm not sure. I've also tried creating a new virtual machine from the same .vdi file but that didn't help.

VM log file please. Minimum information needed for assistance.

Here it is. Host is 64 bit windows 8, guest is 64 bit Xubuntu 14.04.

Hmm. It hardly even seems to start. It looks like your installation has been corrupted, perhaps a registry corruption. I would try installing it again - and make sure to run the installer using "Run as administrator", and also make sure Driver Signature Enforcement is set to at least prompt you when VBox tries to install drivers.

And be aware: you must install VirtualBox while logged in as the correct user, i.e. the user who will use the software. Not "Admin", and this should also be considered if you change account names on your PC.

I don't think it's that. It works OK when I create a new virtual machine with the same parameters from the same .iso file. I believe it's a corrupt header since CloneVDI says: "Source file corrupt - block map contains errors". I've read some people have managed to rescue their .vdi files from that state. Do you know how to do it?

I would expect VirtualBox to give a more informative error if the VDI is corrupt. In fact it doesn't even seem to get that far - e.g. there doesn't seem to be any media atached to the VM.

As to rescue, that would depend on the nature of the corruption. You didn't mention any event that might have led to corruption. Certainly no Windows Update could cause it. If you could give me a few clues then perhaps I could help.

You could try giving me the following information:

• The intended capacity (logical size) of the virtual disk.
• The current actual file size of the VDI on the host - I need an exact size, in bytes.
• A dump of the first (say) 16Kb of the VDI file, zipped up and posted as a zip attachment. You can create this by opening (partial open since the file is so big) with the FrHed hex editor and saving the first 16K to a file which then zip.

• The intended capacity is not listed where I expected (see attached screenshot). Any ideas on how to get it?
  The actual size is 15904800768 bytes.
  The dump is attached.

Thanks!

Well, I don't think there's much I can do here. The VDI header is corrupted so badly that I find it impossible to make sense of. Strangely enough the preheader is perfect. However the header proper seems to be total nonsense. E.g. it claims its own disk size to be 127TB, but no blocks allocated. No sign of a block map either - all zeros up to the end of the 16K provided.

A Windows Update of the host didn't cause this. I don't know what can cause this. Has part of the story been left out?

Regardless, IMHO the only thing that will fix this is a backup copy.

I have no idea then what could have caused it. Windows Update is the only unusual thing that happened around that time. Thanks for trying to help.