Linux recovery from backup problems

[sorveltaja]

I did some VM gpu passthrough testings on Pop os (Ubuntu/Debian flavor), and managed to mess it up, and did a restore from Acronis backup.

It didn't work so well - booting ended in emergency mode. I had to search on the net for instructions of how to look for what might have caused such a failure.

In emergency mode one can use commands, so I used 'journalctl -xb', which prints, I guess, a log of what happens during booting. There was a message like 'timed out waiting for device /dev/disk/by-partuuid/<device id>'. After looking for more info, I found out that it may have to do with device/drive uuid mismatch.

I tried several "how to's" to fix the problem, but none of them seemed to work. Part of the fun is to write down disk id's on a paper, as there apparently isn't easy ways to copy and paste them to a text file in emergency mode..

Using Pop os live (from usb stick), there is an option 'refresh install' to restore the system using recovery partition, but it didn't work either, indicating that the device isn't valid/recognized.

It really gets overly technical in situation like this, so I just wiped whole disk, and made a new installation.

So, what backup methods to consider to avoid such problems?

[Muzzerboy]

Create a clone copy on an SSD or a separate partition, so you can plug it in to replace the dead one? I've done this in the past when attempting a new update installation of Mint and Linuxcnc. Requires a periodic snapshot but has saved me in the past. But I feel your pain.

[vtsteam]

Well, you could have also tied recovering your installation by using a Puppy Linux. I'd recommend using BookwormPup64. This can be written to a thumbdrive, and will run perfectly well from there.

To get the UUIDs just run blkid in terminal.

To copy one, just select it, then Rt Clk and hit Copy. To paste it somewhere else just RT Clk and paste.

if the wrong UUIDs are present at boot, that's going to show up in Grub, your bootloader. Probably in a file called grub.cfg, or menu.lst, or some other similar text file. Using blkid, you should be able to establish what the correct UUIDs are, and edit thm back in place.

Also aboard will be the program gparted. This will examine your disk and show you the partitions and contents graphically. You can check partitions with it or fix them -- not the same problem as a Grub UUID mixup, but possibly also a problem you faced.

As far as backing up goes, for the big linuxes, yes probably imaging the drive will be needed, since grub is often on a different partition that the rest of the linux installation, and you'll need both. For that the dd command in terminal is quite effective, but be absolutely sure you understand how to use it properly -- which drive is being imaged, and which is being written to, or it can wipe out the contents of your drive. I don't have a problem with it.

Puppy linux is easier to back up than the big linuxes because It is very compact (frugal installation) so you really only have to copy your save folder (or savefile if you use one). The save folder (or file) has all of the changes you made to the original puppy installation, and contains your user data. So if you back that up, you can easily restore customizations, installed programs and personal data, using the stock installation media. Grub problems are fixable by correction, no matter how bad, so really, backing up the savefolder, (or file) is all that is needed to be back in business.

Besides Puppy Linux, there is also EasyOS -- similar in many ways (same original author) but designed to use containers, if you like that kind of security isolation -- though it doesn't require their use -- it is particularly well suited to running off of a thumbdrive, though can also be installed frugally as a very compact OS.

I'm working presently on switching from Puppy Linux to EasyOS as my daily driver after over fifteen years with the former.

[sorveltaja]

First I tried dd by following a tutorial. I resized the source partition, as there was a lot of empty space, for it to fit to target device. For some reason, I couldn't get it to write to usb stick.

Next was Clonezilla and Gparted Live, but as that requires rebooting and swapping of usb sticks, it doesn't feel convenient (after I installed the OS on the disk, I used Gparted to erase it, instead of backing it up with Clonezilla).   

Anyway, then was Rescuezilla, which has Gparted in it. No more clumsy mistakes (hopefully).

As a test, after making backup, I erased the disk and rebooted to be sure there wasn't anything to boot on. Then restored backup from usb stick.
On my old laptop, which uses grub, it seemed to be working just fine.