Mirrored Hard Drives

[vaughan.BECKWITH]

To Whom It May Concern,

I created a Virtual machine on Virtual Box 4.1.6 with a guest O/S of Windows Server 2008 Enterprise. This virtual machine consisted of two virtual hard drives, one was on the PC where I was running the virtual machine and the other was on another PC across the network.

Under the Disk Management console on the guest O/S I was able to mirror both of these virtual drives, the guest O/S then proceeded to re-sync both virtual drives with each. However when testing how robust this setup was to simulate power failure, hardware failure, network failure etc. I rebooted the other PC where the virtual drive across the network was located and the virtual machine and its window crashed with the error in the underlying O/S that the Program has encountered an error and needs to close with the Send - Don't Send Error Report option.

The guest O/S simply freezes when I try the same experiment when both virtual drives have finished synchronising

Is this a bug in Virtual Box and does Virtual Box support this kind of setup or will it support this kind of setup in the future as this would be a very useful feature?

Thank You

[vbox4me2]

Did the Host crash or the Guest? to be exact, WHO was reporting the error.

[vaughan.BECKWITH]

The window which is opened by virtual box in which the guest O/S runs, is what crashed. The host O/S reported the error i.e. the O/S in which Virtual Box is installed. The host O/S in this case just so happens to be MS Windows XP.

[vbox4me2]

Ok so the problem is the Guest OS not dealing with the failure, not directly a VBox problem. Any eventlog entries in the Guest? On what basis are you assuming the OS is capable to deal with a failure?

[vaughan.BECKWITH]

Thank you for your reply, I can't reproduce the exact same problem as I described it earlier, but it now produces the Blue Screen, the entry in the events log are

The computer has rebooted from a bugcheck. The bugcheck was: 0x000000f4 (0x0000000000000003, 0xfffffa80015fab30, 0xfffffa80015fae10, 0xfffff800017d2240). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 120811-23078-01. There is not much online concerning this error.

It seems as though the O/S is unable to handle the fact the the mirrored hard drive is no longer available, though we have had physical machines where one of the physical hard drives has failed and the other hard drive takes over. Would this not be a similar situation, how does Virtual Box respond to a virtual hard drive disappearing and how does it inform the Guest O/S?

Vaughan

[vbox4me2]

Depends on who's in control of the main storage, ea. VDI's are managed by the Host so the Host will 'suffer' when a VDI goes awall, iScsi from a Guest is beyond a Host control so the Host won't know or do anything.
In other words:
Create 3 drives, 1 VDI for the Guest OS and 2 iScsi drives inside the Guest remotely mirrored, then disconnect one of the iScsi targets.

[vaughan.BECKWITH]

Thank you for your reply.

I did try what you suggested, however in this case it would suit our purposes to have the guest O/S mirrored, which I tried. When I disconnected the network the first time Virtual Box crashed immediately, the error in the event log for the host O/S is as follows.

"Faulting application virtualbox.exe, version 4.1.6.0, faulting module vboxvmm.dll, version 0.0.0.0, fault address 0x000c3a4b.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

and for the second time, when I disconnected the network, Virtual Box only crashed when I was shutting down the guest O/S, about 1 minute after disconnecting the network. Please see below error present in the event log on the host O/S.

"Faulting application virtualbox.exe, version 4.1.6.0, faulting module qtguivbox4.dll, version 4.7.3.0, fault address 0x001044c2.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

The entries in the event log for the Guest O/S only referrred to the virtual hard drive whic is located over the network as having being corrupted, which really did happen, it is now corrupted and completely unusable.

Would you be able assist me in resolving the above errors?

Yours sincerely

Vaughan

[vbox4me2]

This is not going to work as you want directly, first try the scenario as I described, if that works we'll take the next step in getting what you want.