Getting Blank screen but still showing as Running

[vishnubeema]

Hello,

Recently I installed Virtual Box “VirtualBox-6.1.32-149290-Win” on Windows 10.
Within VirtualBox I installed Ubuntu “ubuntu-18.04-desktop-amd64.iso”.

If I keep opening Ubuntu and after sometime I see blank screen. Not sure how to come out of the same.
I am attaching VM log along with screen shot. Please let me the reason behind this issue and how to come out of this.

Strange thing is, after closing forcefully and start again, I done see my previous contents. How to see my old view with all my installations.

Thanks & Regards
Vishnu Beema

[mpack]

00:00:02.486511 Host RAM: 15761MB (15.3GB) total, 8190MB (7.9GB) available
00:00:03.751538 CPUM: Physical host cores: 4
...
00:00:02.673231 RamSize <integer> = 0x0000000200000000 (8 589 934 592, 8 192 MB, 8.0 GB)
00:00:02.673354 VRamSize <integer> = 0x0000000008000000 (134 217 728, 128 MB)
00:00:02.673230 NumCPUs <integer> = 0x0000000000000004 (4)

Your VM settings disregard what resources you have available. Resources not only have to be present, but available, i.e. not already in use by the host OS or another running app.

Reduce VM RAM to 6GB and CPU cores to 2.

I just noticed that this is a cross-post, which is against the forum rules. Locking this.

Previous post was here: viewtopic.php?f=6&t=105637.

[vishnubeema]

Hello,

Since below ticket is locked, I am raising one more ticket.
viewtopic.php?f=6&t=105647

This issue is different from
viewtopic.php?f=6&t=105637

As shown in snapshot, after hang / blank screen, I tried to reset. But when I selected "Power off the machine" along with "Restore current snapshot" VM got shutdown. But after starting once again all my data lost. How to recover the same. Now I am not able to see all my data.

I am attaching the log when this issue occurred. Please let me know your inputs.

Also I am attaching screenshot of my "Snapshots" folder (Snapshots_Folder.png) and Virtual Box (VirtuaBox_settings.jpg). Whether by changing any of these settings can I restore my previous view with all my installations.

Thanks & Regards
Vishnu Beema

[mpack]

I merged your post from a third topic which you created to discuss the same problem that was already addressed in the first two, (the second is now above): you are over allocating RAM and CPU. Reduce your VM's RAM to 6GB and reduce VM cores to 2.

Posting variants of the same question multiple times is called cross posting, and it is against the forum rules because it wastes the valuable time of our volunteers who end up answering multiple times.

Please do not cross post again.

Also, please do not post any more logs until you have made the changes I asked for. We expect people who ask for advice to act on it.

[vishnubeema]

Thank you for your inputs.
I feel its a different issue as I lost my data and not able to recover. Whereas previous post is on "Guru Mediation", but I did not lost data during that scenario.
Even after changing to 6GB RAM and 2 CPU. I attached all required logs and screenshots.
Please let me know how to recover my data so that in future I will avoid such scenarios.

Thanks & Regards
Vishnu Beema

[mpack]

The basic answer is that data can be recovered from your last backup of the VM.

But: a guru meditation would not normally result in data loss, assuming you are talking about data lost from disk rather than from RAM. Data written to persistent storage (disk) can't just disappear if the host hardware is working. So to address the data loss we would need to understand whether it was caused by corruption or by deliberate user action, e.g. reverting the VM to an earlier state.

[vishnubeema]

Hi,

My Host hard is working and not corrupted. I feel some issue with "by deliberate user action, e.g. reverting the VM to an earlier state.". As mentioned in snapshot, I selected "Restore current snapshot". Will this cause issue.

I this cause how to get old setup with all installations.

Thanks & Regards
Vishnu Beema

[mpack]

There is no operation called "restore current snapshot". But if that means to restore to the most recent snapshot then yes: it involves discarding all changes to the VM done after that snapshot was created. The amount of data discarded would depend on how long ago the snapshot was created and how often the VM is used.

Indeed this is why snapshots are used by some - it allows you to try things inside the guest OS and then quickly undo them. Unfortunately people often assume that because they have multiple guest states it means they don't have to back up any host states, which is far from true. If you deleted files on the host (or asked VirtualBox to do so) then they can only be recovered from an actual backup of the VM folder.

Experienced users do not use snapshots. Instead we use real backups, ideally to external storage, since that protects against failure in both host and guest.

[vishnubeema]

Hi,

I am new to Virtual Box.
As shown in "Data_lost_After_selecting_Restore.jpg" snapshot, I selected "Restore current snapshot". After that, I restarted VM and not able to see my previous data.
Even I backed up all my files as shown in "Snapshots_Folder.png" snapshot. With these snapshots whether can I recover my previous installations.

I might be doing some wrong. Trying to understand to avoid same mistake in future.

Thanks & Regards
Vishnu Beema

[scottgus1]

Please, Vishnu, stop making new topics about this problem. You were warned about doing that above, and you did it again. That's getting really close to requiring a time-out from this forum. We really want to help you, but we need you to obey the rules, too, just as we obey them.

*****************************

I selected "Restore current snapshot". After that, I restarted VM and not able to see my previous data.

Snapshots are made in an order, with a "current state" at the end of the chain. Example:

Base state > Snapshot 1 > Snapshot 2 > Current State

"Current State" holds all the changes made since the last snapshot was made. If you restore the current snapshot, this clears and empties the existing current state. All data since the last snapshot is deleted.

So the result you see above, "not able to see my previous data", is expected from this: "selected "Restore current snapshot" ".

Virtualbox is working and did exactly what it was instructed to do.

*****************************

backed up all my files as shown in "Snapshots_Folder.png" snapshot. With these snapshots whether can I recover my previous installations.

As you can see, we did not receive your png file. But if you had a backup of this VM's files before you restored the current snapshot, you might be able to get (some of) the backed-up data back.

Use Mpack's CloneVDI to clone the latest snapshot disk file that does not throw an error in CloneVDI. That disk clone will contain the latest state of the data you have successfully backed up. You can either build a new VM around that disk clone, or attach the clone to a VM to extract the data out of it.

*****************************

Trying to understand to avoid same mistake in future.

Use an experimental VM to see exactly what snapshot commands do. Snapshots are a powerful but dangerous tool. Learn them well before relying on them, and use them wisely. Full regular host backups are always a requirement when using any computer nowadays.

Or stop using them altogether. Use backups and full VM clones to work with previous VM states.

[vishnubeema]

Hi,

1) I replied because of your statement "---There is no operation called "restore current snapshot".--- " but I see the same in the attached snapshot.

2) For your comment "---- we did not receive your png file -----", I am not sure whether you unzipped "Data_lost.zip" attached. All snapshots are within.

Sure I will take care of snapshots. Thank you for your inputs.
You can close the ticket. If any further issues, I will raise a separate ticket.

Thanks & Regards
Vishnu Beema