On-disk format change beckons for brave early adopters of Bcachefs

New versions of the two leading next-generations filesystems are coming: both OpenZFS 2.2.3, and some time afterwards, an improved bcachefs. Kernel 6.7 only appeared last month and as we wrote at the time, it finally included the next-gen bcachefs filesystem. We say finally because it didn't make it into 2023's kernel 6.5, …

[l8gravely]

I don't trust btrfs either...

I've had multiple VMs get totally corrupted when trying to take a snapshot before the upgrade from Suse SLES 12.5 to 15.x, which they say you can roll back to if there's a problem. Not too likely. I had several systems work... but several also went completely sideways and couldn't be recovered. So I'm *really* leary of btrfs with my data. Right now I stick with ext4 and xfs, but hoping bcachefs becomes stable and reliable and performant all at once. snapshots and sub-volumes are going to be really useful down the line.

[Spazturtle]

Re: I don't trust btrfs either...

Yeah I have lost systems to btrfs before as well, every time they promise it is now stable some new data eating bug pops up.

[Liam Proven]

Re: I don't trust btrfs either...

Thanks for this, both.

Just on a personal level, I am really glad to hear it's not just me.

I worked for SUSE for 4 years, and it was a great job at a great place. I enjoyed it a lot, and installing my own copy of openSUSE when I got there was a pleasure: it's just as good as it ever was, including back when it was my default desktop OS around 2001-2004 or so.

(Compare and contrast with Fedora when I worked at Red Hat. My staff-issued laptop was not fully supported by the company-issue laptop _as used by the people developing the OS_. "Oh, yes, we know the trackpad doesn't work right, and no, you can't fix it. Just turn it off. No, the fingerprint reader doesn't work either." And so on.)

But my work openSUSE desktop *and laptop* computers self-destructed once or twice a year, and the company in-house attitude was "it's just you, you're doing something strange or foolish. Btrfs is fine. It's the state of the art in Linux filesystems. It's bulletproof. It's just you."

I think it's notable that before Btrfs, openSUSE used XFS, and before XFS, it used ReiserFS. Somewhere in the company is someone who likes fancy filesystems.

In the end, I reformatted my system with root on ext4 and /home in a separate partition, also on ext4, and then, it became bulletproof. My colleagues thought I was made for sacrificing snapshot support, but I no longer needed it.

I see it as a critical weakness of a very solid distro, and I hope that they soon extend Snapper support to bcachefs, in which case this could be an amazing distro with unique abilities.

[ChrisElvidge]

ReiserFS

I used Reiserfs for years when I first started with Linux in the early '90s. Far better at recovery than anything else available at the time. Shame it isn't/wasn't developed further.

[RedGreen925]

Re: ReiserFS

"I used Reiserfs for years when I first started with Linux in the early '90s. Far better at recovery than anything else available at the time. Shame it isn't/wasn't developed further."

Yes I used it for years myself but went with ext4 after its demise due to lack of development. Which is kind of hard to do when the driving force behind it, Hans Reiser, is in jail for murdering his wife. The free software community dropped it like the plague after that happened.

[Denarius]

Re: I don't trust btrfs either...

same here. Lost /. Not able to recover it using forensic tools enough to find a log entry explaining why. Fortunately I keep /home and data partitions on XFS or if I must, ext4 as well as backed up. Looking at you AntiX.

[YetAnotherXyzzy]

Re: I don't trust btrfs either...

Me too. I'm big openSUSE fan. I've been told, probably correctly, that I'm as bad as the Apple fanbois. But even I draw the line at their penchant for not-ready-for-prime-time filesystems, having been burnt too many times. Now it's EXT4 on all of two partitions, / and /home. I haven't had a problem in years, and if I ever do EXT4 has more and more robust recovery tools, and more tutorials written about them.

[Anonymous Coward]

Re: I don't trust btrfs either...

I had btrfs fails on SLES a couple times in the past. Stuff like system disk partitions filling up, though there was nothing extraordinary happening to the machine, the sysdisk wasn't particularly small, and I'd simply accepted SLES defaults during install. Didn't really know what else to do at the time.

I would've been happy to believe "you're just doing it wrong" if I'd ever found a solid explanation, but even in that case: why did the installer use defaults that blew up later?

SUSE itself was fine -- I quite liked parts of it, and would consider OpenSUSE today as an alternate to Red Hat shenanigans.

But I can't say I'd accept the default btrfs filesystem choice -- I'd probably select one of the other options at this point.

[Andy Mac]

What is a BCA Chef anyway?

[Liam Proven]

Um. Yes. Quite.

FWIW, not a lot, bcachefs evolved out of an earlier caching system that wasn't a full filesystem.

B-tree -> bcache -> bcachefs.