virtualbox.org

I recently figured out I had a bad stick of RAM in my PC that has probably been acting up for about a month (in hindsight, because weird things started happening then.) While I have reinstalled my host (Windows 8.1) and begun working on all that, my guests are another story.

Most recently I was working with my Ubuntu 12.04 VM, and it probably got hit the hardest by the bad RAM. However, I have a dozen other VM's that I have at least touched in the past month. The bad RAM could have been there longer too (I've had it for 6 months but it tested fine back then,) and I have like 20 VM's that I can't fully trust.

Anyway, I don't have backups of these VM's, as losing any one of them was not a concern, and I frankly don't have the means for backing them up. But I would rather not have to rebuild all of them.

TL;DR: I have one XP VM which I made a snapshot of. Right now I am debating whether it is safer to restore the snapshot, or leave it as-is. If I understand correctly, all changes since the snapshot are written to a different file than the main disk image, so I believe restoring the snapshot should be the safer route. Deleting the snapshot would in fact write the more recent and potentially wrong data to the older disk image, correct?

Any advice would be appreciated!

Understandably having a bad stick of ram is a big deal, but... what makes you think that your guests are now corrupt?
Now had you said your hard drive was failing that would give me concerns, but the only way to find out if the guests are effected is to boot them and see. Chances are they will be fine.

Ubuntu 12.04 wouldn't startup correctly (the desktop wouldn't load) Also, (again in hindsight) I had an error when installing package updates last week where there was a "." instead of a ">" in the package dependancies. (that is consistant with a single bit error.) so basically I know that VM has some issues, and in the same time I installed a new 14.04 VM that just wouldn't behave, but that is completely expendable.

On the other hand, I understand debian packages are signed, so at least that reduces the potential for errors to the last disk write.

In the meantime, since virtualbox 4.3.10 was released on march 25, I have at least started half my VM's to install OS updates and the newest guest additions. Most likely I'll just wait and see, as there is nothing mission critical, and if errors arise, rebuiild each VM as needed.

BTW the errors were worst in the last week with blue screens etc, and yes I have put in fully tested RAM since then (the old was throwing a LOT of errors on memtest86+), while I wait on the RMA.