[SOLVED] No booting anymore after setting up Timeshift on an external drive

[ralfheinz]

Hi all,

trying to boot my system pauses at the blinking Kubuntu logo. After I while the logo disappears and I get this (sorry for the bad photo):



What I did before: Formatted an USB stick with 2 partitions (both with ext4), setup an automatic Timeshift snapshot plan targeting partion 1 and a backup plan for personal data with KBackup targeting partition 2. Both processes worked as expected. Later I unmounted both partitions and shut down the computer. Starting it after led to the situation above.

Unfortunately I don’t even know where to start. Pressing Control-D seems to do different things, currently I receive the message 'Failed to start default target: Transaction for graphical.target/start is destructive (emergency.target has 'start' job queued, but 'stop' is included in transaction' – printed in red to underline the hysterical tendency. I tried some of the other options before and don’t remember which one it was, but one time I received a long list with several hundred green OKs contrasted by the red/orange lines 'Failed to mount partition_name' and 'Dependency failed for load file system'. (partition_name is the target partition for Timeshift.)

Obviously the problem is at least connected with the USB drive and/or Timeshift. One time the boot immediately worked after I plugged in the drive, but that happened only once. It’s hard to imagine an USB stick has to stay mounted forever, otherwise the system will break, but that is what it looks like.

Any ideas what I could try?

[oshunluvr]

So press Enter and type journalctl -xb

[ralfheinz]

oshunluvr Thanks! I did that and received 2353 lines of text (barely readable as the display is a MacBook Retina with supersmall text here), ending with:

media-username-partition_name.mount: Job media-username-partition_name.mount/start failed with result 'dependency'
dev.sdc2.device: Job dev.sdc2.device/start failed with result 'timeout'
(partition_name is the 2nd partition this time, keeping personal backups, not Timehsift snapshots)

[oshunluvr]

I'd boot to a liveUSB and see what's up with that drive. If it's in your /etc/fstab and you don;t need it to boot, take it out of fstab and reboot.

Also FYI, I created a post on here about how to set the font size in terminal mode (and grub) to a larger size so it's readable on hires screens. Once you get this fixed, you might consider doing that.

[oshunluvr]

Edit /etc/default/console-setup and change FONTSIZE="8x16" to FONTSIZE="16x32" and reboot

[ralfheinz]

oshunluvr Great, that worked immediately, thanks a lot! Very good idea to start from a liveUSB, though I have to admit that I should have figured that out by myself – okay, hopefully next time. I also followed your font size hint, the result is more than helpful, thanks for that too!

[oshunluvr]

Great indeed!

If I follow your comments correctly, the backup drive(s) is on a USB and it was mounted in fstab? If this is so, it's not really a good way to use a thumb drive - as it seems you found out. fstab is for "fixed" disks and not well suited for removable devices for reasons like this one.

Generally, when you insert the removable drive you should see a popup that has the option to mount it and/or Dolphin can mount it. In this way, the USB file system is assigned to your user (except EXT4) and makes access easy.

If you do not intend to remove the USB device ever or only plan to unplug it occasionally - you should be able to enter it into System Settings > Disks & Cameras > Device Auto-Mount and it will mount.

If you want to control the mount location (somewhere other than default), you can create a UDEV rule for that specific device that will mount it.

[ralfheinz]

oshunluvr Yes, both partitions had a line in fstab. I really don't know how they landed there, I didn't actively do anything for it. So I deleted both lines and the problem was solved.

Funny thing is that I use a lot of external drives and never had serious issues. Main difference: they are all formatted in HFS or FAT for cross platform usage. Beside the internal SSD the mentioned USB stick was the first drive I formatted and partitioned on Linux to be exclusively used as backup drives for this machine. I did it with KDE Partition Manager (not sure about its English name), gave both partitions a name and the app setup mount points for them. Only thing I did after was setting up the two backup plans. So somewhere during this process the fstab entries must have been written.

Usually external drives work exactly as you describe it, one constantly plugged SD card automatically mounts on startup (OK, with occassional failures) some other 'known' drives automatically mount after plugging them in (there was a setting option somewhere, I think in the popup). None of them seems to have written anything in fstab.

[oshunluvr]

I would guess Timeshift did the fstab edit. Regardless, glad it was an easy fix.