[Solved] Hard disk data loss

[whatdhack]

Why the vmdk, was it from another install? -- it was an export from another host i think
Why the 2Copy, was it original a bootable container? -- the original was running out of space .

[whatdhack]

I think I have spotted the problem . The ubuntu-xenial-2Copy.vdi and ubuntu-xenial.vdi shares the same UUID and that confuses ubuntu .

[socratis]

• You were using "ubuntu-xenial-2.vdi" as your boot disk.
• That disk was running out of space.
• You copied that VDI outside of VirtualBox to "ubuntu-xenial-2copy.vdi".
• You attached that as your bootable drive and you kept "ubuntu-xenial-2.vdi" as a secondary drive to copy things from the old one to the new one.

Do I have it correctly?

[whatdhack]

I think the process also involved some dd and parted acrobatics- been a while since I did that. One of the 2 drives with same UUID is selected randomly at boot I guess - that will explain the issue. Any other subtle issues that can arise from having the same UUID for multiple partitions ?

Hope that takes care of disappearing data issue.

[socratis]

We're now at post #34. I don't usually quote whole messages, but I'll make an exception and refer you to my first response to your original post in this thread, post #2:

You'll definitely have to give more details about your setup, but let me additionally ask you a question: did you lose the whole VDI or did the VM revert to an earlier state? This, again, to more complete and thorough description of your setup, the circumstances and the exact errors. See: Minimum information needed for assistance. Plus a lot more than the basics if you want us to have any idea about what's going on.

You can't simply throw a "hard disk loss", "is this a known issue?" and expect any serious answer. Of course it's not known that VirtualBox loses its data.

If you had only replied at that point with something more that Tweeter-length answers, we could have spared a couple of back and forth posts. Or more...

Any other subtle issues that can arise from having the same UUID for multiple partitions ?

It depends. Wrong boot is the easiest to figure out, that's why I believe Perryg was suspicious and asked for complete and full details about the "...copy.vdi", he was on to something. This cannot happen in real life easily, so it's untested territory. That's why VirtualBox provides its own "Copy medium" mechanism, where one of the things that changes is actually the UUID. Because the "UU" stands for "Universally Unique" and there are algorithms that make sure that actually happens.

Since you reverted back to February, and you do have a backup (great!), I would simply start with a fresh approach and follow the procedures that you would if you wanted to replace your current physical hard drive with a larger one, i.e. boot from a live GParted CD and 'dd' the old to the new. And then store the old VDI somewhere safe. Or keep it as a read-only medium.

[whatdhack]

socratis, i think your request is not reasonable - no one remembers all the steps and details , specially if those were done a while ago. you can harp , yell, scream, abuse , but that is not going to make some one remember all the details. it is just plain unpleasant, and pretty ineffective. hence , looking at logs, config files etc are much better way to root cause issues as the other person did .

[socratis]

We had two options with the specific problem at hand:

1. The owner of the system backtracking and remembering what they did. When asked pointed, specific questions about things that look suspicious. Which cannot be extracted from any log, config file, or anything else, unless you know exactly to look for that specific piece of information. You should thank your Queen Luck that you did not rename the VDI and you kept the "copy" in the name there.
2. A couple of complete strangers to the system, trying to reverse-engineer remotely with no access, what might have gone wrong with the owner's system, based on half-baked answers, accusations of poor support, persistence that they knew the symptoms better and an attitude to spare.

You're right, my expectations/requests were not reasonable. I should have looked harder into my crystal ball trying to decipher and figure exactly what you did to your system, because you couldn't/wouldn't bother to squeeze your memory hard enough. My mistake. It won't happen again in the future. That, I'm sure of. No details, no answer. Problem solved.

I'm outta here...

[whatdhack]

socratis, i provided you whatever you asked for ( the ones that did not get lost in your verbiage). as i said, screaming , yelling, abusing about remembering what someone did a while is not productive . looking at logs, configs , etc is far more productive and may i say significantly more pleasant.

you are a moderator of this list , so here is a feedback to you. this list has been helpful, except someone being very unpleasant.

[socratis]

this list has been helpful, except someone being very unpleasant.

Yeah, I get that from time to time. Honestly, I prefer "unpleasant and correct" rather than "stubborn and incorrect". There's that 2% of the people that are know-all and at the same time have their sensitivity senses super-charged, so much so, that if you tell them that they might be wrong, they get offended. I can't do anything about that unfortunately. Characters and personalities are formed during adolescence. Now it's too late to try and change that 2%. Unless you're still in adolescence and there's still hope...

I'm honestly glad that you discovered your mistake after all, the fact that you copied the file outside of VirtualBox and that messed things up. As we've all been saying all along, this is not something that VirtualBox could do or is responsible for.

I'm going to mark this thread as [Solved].