[FIXED] Failed to load unit 'hda' when restoring session

[jrc55]

Thank you pentagonik for the new builds.

I recognize those were probably meant to fix the problem of Tim Thein but I thought I'd keep you informed and add that 5.0.13.r104900 did NOT fix my problem. One step at a time and I look forward to future progress.

Host is Win 8.1 with 16 GB
Guest is Fedora KDE 64 with guest additions. 3GB memory
This is a clean install of a VM guest using Fedora 23 KDE 64bit made with 5.0.12. I cannot restore to a snapshot made using the 5.0.13.r104900.

VBox throws a ...
Failed to load unit 'hda' (VERR_INVALID_PARAMETER)
see attached.

If there is a sequence of events I should follow regarding old/new snapshots/etc then please advise.

[jms-vbox]

Latest test version 5.0.13-104900-Linux_amd64 still has the original issue. But disabling audio from Windows 10 guest's settings fixes the problem for me too.

[harley-peter]

The workaround from Tim Thein works for me. After the procedure with audio deactivation and reactivation I saved and restored the session several times and it works. Thank's Tim.

[TimThein]

Tim,

Your fix partially works for me. Please let me know if you see anything wrong below ...
1. discard state from a snapshot that fails to restore..
2. change to audio off
3. boot and create a new snapshot. That snapshot can be successfully restored. Good info and maybe critical to the final solution.
4. shutdown
5. turn back on the audio
6. boot and create a new snapshot. For me that snapshot can NOT be successfully restored. But I'm not sure why it would. I'm back where I started from before these tests.

I too was using 5.0.12
Thanks for your time.

I did not do anything related to snapshots. All my steps were related to the saving and restoring the execution state. Maybe the term 'snapshot' does not mean what you think it means.

Maybe you need to worry about saving and restoring the execution state for one snapshot before mixing in steps to create another snapshot. So, discard the saved state, boot from whatever snapshot you like, log in to Windows 10 VM, save the execution state, and restore it. Then save and restore the execution state again.

[scottgus1]

For the proper terminology, to avoid confusion:

A "snapshot" in Virtualbox is a point-in-time in the life of a guest that one could go back to. Imagine taking a "snapshot" of yourself as a 17-year-old. In some sort of science-fiction fashion, you decide when you're 30 that you'd like to live your life in a different way. You pull up your "snapshot" and suddenly you're 17 again. This is basically how a Virtualbox snapshot works.

A "saved state" is very similar to a Windows hibernation: the guest stops executing everything and pauses, then shuts off. When the guest is started, it is supposed to pick up from where it paused as if nothing happened in between except the passage of time.

[jrc55]

Tim Thein and Scottgus1 ... Thanks for the help but your technique did not work for me.

1. got rid of all my snapshots ... to avoid confusion
2. started the guest
3. saved the machine state
4 starting the guest again fails with my error .... Failed to load unit 'hda' (VERR_INVALID_PARAMETER)

If I added a step 1B to turn off the audio then I can successfully start the guest after saving the machine state. But once I shut down the VM so as to turn back on the audio then I'm back to where I started : unable to save/restore a machine state or a snapshot.

This was done with 5.0.13.r104900

Maybe it's related to my guest being Linux. ??? Anyway .... I do appreciate the efforts and I'm open to any more suggestions if you have any.

[TimThein]

You might want to try describing your problem in another forum. In case you didn't realize, this forum is for Windows Guests.
Or you might want to downgrade to 5.0.12. The steps I performed were on that version.
Also, I'm running VirtualBox on Windows 7 Enterprise 64 bit and my guest OS is Windows 10 Enterprise 64 bit.
I hope you find a solution soon.

[jrc55]

Thanks again Tim.

fyi ... I originally posed my thread in a thread the "Using VirtualBox" section because there was a thread about the use of 5.0.12, but I was asked to move to this thread because it already had a developer lined up.

[Martin]

Or you might want to downgrade to 5.0.12. The steps I performed were on that version.

Do you still test with 5.0.12?
The 5.0.13 is the testbuild version provided by pentagonik a few posts before to fix these problems.

[pentagonik]

Another testbuild 104913 is available here: https://www.virtualbox.org/wiki/Testbuilds

[jrc55]

I get the same error with 104913 ... Failed to load unit 'hda' (VERR_INVALID_PARAMETER)

If it matters .... the guest additions is at 104829.

I've attached another log. Let me know if there's anything else I can do.

[TimThein]

Or you might want to downgrade to 5.0.12. The steps I performed were on that version.

Do you still test with 5.0.12?
The 5.0.13 is the testbuild version provided by pentagonik a few posts before to fix these problems.

I never tested with the test build until this problem came up. I briefly test with 5.0.13 and found that it didn't resolve my problem and so I downgraded back to 5.0.12.
I'm tempted to upgrade again to the test build because even though I came up with a work around, that work around is now failing partially. I say 'partially' because saving and restoring the execution state only works when audio is disabled. I would rather shutdown and boot up than do without audio since I rely on audio so much.
I guess it's time to try the latest test build and hope for the best.

[TimThein]

104913 didn't resolve my issue. BTW, my additions is still 104815.

[harley-peter]

Code: Select all

Your fix partially works for me. Please let me know if you see anything wrong below ...
1. discard state from a snapshot that fails to restore..
2. change to audio off
3. boot and create a new snapshot. That snapshot can be successfully restored. Good info and maybe critical to the final solution.
4. shutdown
5. turn back on the audio
6. boot and create a new snapshot. For me that snapshot can NOT be successfully restored. But I'm not sure why it would. I'm back where I started from before these tests.

I tried this workaround on two computers with a Linux host and it works on both machines. On the contrary of point 6 of Tim on my machines I can restore the saved snapshots without a problem. Maybe the reason is the Linux host.

[jrc55]

Thanks harley-peter for the extra info. It should be helpful to the developers in that they may be able to eliminate the problem being for Lionux hosts too. But I feel you are right that your rig being a Linux host and mine being Win 8.1 make the difference.