Btrfs system crash, howto recover?

[birdibird]

As this is the daily laptop of my partner. What would you recommend: which fs to use?
She’d like to just use the laptop without thinking to much about tech background, but with an easy possibility of restoring a snapshot when needed.
I thought that btrfs would be nice for that, but that may be my mistake.
Any other recommendations?

[Nachlese]

@birdibird

As this is the daily laptop of my partner. What would you recommend: which fs to use?

If you don’t know or even want to know
(that’s not a problem - just a practical evaluation …)
the intricacies of BTRFS …

don’t use it.

especially if it is not your own system, but someone elses

ext4 is much easier to handle

If a file system fills up near 100%
there is always going to be problems.

Whether you’d

@birdibird

like to just use the laptop without thinking to much about tech background

or not.

Choose ext4.

BTRFS (and it’s maintenance) is just very different

[birdibird]

Yes, we’d been speaking for some time now that she needs to delete some stuff from her laptop as it was filling up. But well, as you know, life came in between and she had started but not removed a significant chunk. Well, I guess now she learned not to wait

edit: and we might buy a new bigger internal ssd

[Nachlese]

I would not burden myself or you or her or you with that.
Just choose ext4 next time - the impact won’t be so severe - and the learning curve not so steep.

… who want’s to keep track of the percentage the file system is used … ?

You probably should need to have had a good reason to set her up with that file system …

[birdibird]

@Nachlese

… who want’s to keep track of the percentage the file system is used … ?

True.

After finishing the backup, I am considering even wiping her ssd and reinstalling.

As said above, I was looking for a robust system which had easy snapshots rollbacks. Ext4 doesn’t have that the way btrfs can provide.
What about other fs like f2fs or XFS or ZFS?

[Nachlese]

@birdibird

What about other fs like f2fs or XFS?

I would not know.

But:

@birdibird

a robust system which had easy snapshots rollbacks. Ext4 doesn’t have that the way btrfs can provide.

I would not subscribe to that - that is either just wrong - or colored by opinion/prejudice.

… what did you expect from BTRFS which ext4 could not provide? …

[birdibird]

@Nachlese

… what did you expect from BTRFS which ext4 could not provide? …

Easy on the fly snapshots of system (@) which doesn’t cost a lot of extra space, to be able to rollback if some update goes wrong.

[Nachlese]

@birdibird

Easy on the fly snapshots of system (@) which doesn’t cost a lot of extra space, to be able to rollback if some update goes wrong.

… and that’s not possible with ext4 ?

even if it wasn’t:

How is that helping her?
… not suspecting quite serious problems when filling up the file system up to the brim?

… use a file system that you can easily manage

in this case, for ext4, the remedy would have been:
tune2fs -m 1 /dev/sdxy
and you’d have instantly had 4% more usable space

[birdibird]

I am not sure what you are implying here.
It is already clear that having an almost full system is not a good thing. Everybody learns from it for the future.

[Nachlese]

@birdibird

I am not sure what you are implying here.

you are not?

@birdibird

It is already clear that having an almost full system is not a good thing. Everybody learns from it for the future.

hopefully

[birdibird]

I backuped and removed her music folder. That saves 107GB.

[birdibird]

@Nachlese

in this case, for ext4, the remedy would have been:
tune2fs -m 1 /dev/sdxy
and you’d have instantly had 4% more usable space

ok, got it. thanks

[Nachlese]

@birdibird

ok, got it. thanks

Sure?

Whatever the case.

Don’t use BTRFS unless you understand it.

I confess:
I don’t.
That is why I do not use it.

[birdibird]

Well, don’t we all learn by doing or using something?
And helping each other in learning more?

[birdibird]

Thanks @andreas85, your contribution has helped a lot to understand the out-of-space situation.
After backup and removing the music folder, the laptop booted back into the system.
The kernels had no problems: 6.8 and 6.10 both booted fine.

[Nachlese]

hopefully
even:
certiainly

[Kobold]

@birdibird

And yes, I prefer to not use the rsync but the btrfs snapshots of timesync exactly for the reason of the power of btrfs.
But now that I need it, it doesn’t work

@Molski

Kobold will recommend Timeshift with rsync pseudo snapshots to anyone, regardless of your setup, needs, or filesystem type(s).

Well i don’t wrote Rsync recommendation this time… because i was thinking that he maybe wants exactly this.

On the otherside, he has no way to restore his system with a simple rollback now.

The valid question is now… was it worth to use Timeshift this way?

I think its a clear no, but on the otherside he saved time to create snapshots… Snapshots where he can’t rely on it now.

@birdibird

If I boot into the liveusb I can see them in the Timeshift gui, but clicking restore there doesn’t give me a bootable solution.

You are not the first one who run into this exact problem, where your (BTRFS/Rootstored) Snapshots are gone now.

Its exactly as @Nachlese wrote here:
BTRFS is a advanced filesystem, use it only if you know what you doing.

@Molski That doesn’t mean that im against BTRFS or in a war against this Filesystem, the user just should get his homework done before he start using it and if the user isn’t willing to do this, BTRFS shouldn’t be recommend then to this user.

And i saw you get caught on surprise recently in another BTRFS Topic, where you didn’t know that repairing a file with FSCK can lead to even more dangerous situation, when the whole BTRFS Partition is in the read mode. (if i understand that recently topic, correctly).

@Zesko

There are some reasons:

• File corruption is not the same as filesystem corruption:
  • If only specific files are corrupted but the filesystem itself (including metadata) works properly (i.e., It can be mounted and read), this is usually not an error at the Btrfs level.
  • File corruption can happen due to checksum mismatches, often caused by bit failures in hardware, it doesn’t mean the whole filesystem needs to be repaired. This is why it’s recommended to use btrfs scrub instead of btrfs check --repair
• btrfs check --repair is designed to repair critical filesystem corruption, especially when the filesystem cannot be mounted or is severely damaged. However, sometimes it succeeds (luckily), while other times it can lead to data loss after running the repair option.
• Running btrfs check --repair on the working filesystem can be risky, as it might inadvertently cause more harm to the metadata or data structure.

[birdibird]

@Kobold Well, in the end it turned out it wasn’t about timeshift, so I couldn’t check if the rollback actually works. As andreas85 explained correctly it was the out-of-space problem, where while thinking 12,3GB was available, there was not. After solving that, the system booted fine.
So, lessons learned about btrfs

[Kobold]

@birdibird

I backuped and removed her music folder. That saves 107GB.

Pamac Cache (default is the last 3 version) you can reduce it to 1, this saved also a good amount of space.

@birdibird

Easy on the fly snapshots of system (@) which doesn’t cost a lot of extra space, to be able to rollback if some update goes wrong.

Besides the shorter snapshot time creation (because they consume less space), Timeshift with Rsync on EXT4 is more reliable and its more easy to restore.

[birdibird]

@Kobold

if the user isn’t willing to do this, BTRFS shouldn’t be recommend then to this user.

This cannot be an assumption. I thought of course when I researched filesystems I did my homework: But somehow haven’t come accross the out-of-space issue of btrfs at that time.