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Comment by F00Fbug | Hacker News Reader

I've been in the same boat. Around 2012 or 2013 I put BTRFS on my DIY NAS/media server. For some reason, totally unprovoked the array just went belly up with no warning or logs. I tried and tried without success and couldn't recover it. Fortunately I had good, recent backups and restored to ext4+LVM and I'm still there 10 years later.

BTRFS sounded cool with all it's new features, but the reality is that ext4+LVM does absolutely everything I need and it's never given me any issues.

I'm sure BTRFS is much more robust these days, but I'm still gun shy!

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In 2019 I was setting up my new computer at my new job, and the Ubuntu installer had btrfs as an option. Figuring that it had been ages since the last time I'd heard about btrfs issues, I opted for that.

A week later, the power failed in the office, and my filesystem got corrupted. In the middle of repairing, the power dipped again, and my entire fs was unrecoverable after that. I managed to get the data off by booting off a separate drive and running a command to extract everything, but it would never mount no matter what I did.

I've never had an issue with ext4, xfs, or zfs no matter how much I've abused them over the past 10+ years, but if losing power twice can wipe out my filesystem then no thanks, I'm out.

(Plus: non-recursive snapshots? No thanks.)

Yeah...I used to live in an old neighborhood with above ground lines and huuuge trees. Every strong windblow would flip the power out for a second. Some days a few times a day, some days never.

EXT4 has never once failed me, and I personally battle tested it by working while losing power probably a total of 200 times. I probably should have bought a UPS come to think of it.

Was it RAID5/6? If not that's worrying. I've had one BTRFS system eat itself to the point that it could only be mounted read-only, but no data loss.

Not the OP, but I deployed btrfs on tens of embedded systems that had their power consistently cut on a daily basis. Ended up with unmountable filesystems repeatedly. Switched to ext4 and never had an unmountable filesystem again.

These were single disk systems, no raid at all.

Are you sure you never had an issue, or did you just not notice? Ext4 and xfs can mangle your files and never let you know because they don't checksum. This comes up often in comparisons and I wish people paid attention to the difference.

Gonna pitch in my anecdata:

Around the timeframe you mentioned, I lost a BTRFS filesystem when I filled it up. Probably could have recovered it if I had known more, but oh well. I definitely feel the gun-shyness!

However, I'd want to add that at a previous job, I had a ext4 fs go belly-up in a similar way. One day, just died without warning. Maybe could have recovered it, but like others have mentioned we'd have no guarantees about the data.

Moral of the story is, of course, always have backups :)

I sort of had the same experience, dropped it for a decade, and came back around. It's a lot more robust these days. Also the btfsmaintenance tools take a lot of the load off of an admin. I just use the default settings and don't have any issues.

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