Also, impressive work!
I wonder how could a requirement like that possibly arise. Especially with an obvious exception for zfs.
Also out of tree.
Just talking about filesystems with checksumming (and multidevice). Any new filesystem to support these features is going to be newer.
I've had both btrfs and bcachefs multidevice filesystems lock up read-only on me. So no real data loss, just a pain to get the data into a new file system, the time it was an 8 drive array on btrfs.
The btrfs solution has a mixed history, and had a lot of the same issues DRBD could get. They are great until some hardware/kernel-mod eventually goes sideways, and then the auto-heal cluster filesystems start to make a lot more sense. Note, with cluster based complete-file copy/repair object features the damage is localized to single files at worst, and folks don't have to wait 3 days to bring up the cluster on a crash.
Best of luck, =3
I've been using ZFS for my NAS-like thing since then. It's been rock solid ().
(): I know about the block cloning bug, and the encryption bug. Luckily I avoided those (I don't tend to enable new features like block cloning, and I didn't have an encrypted dataset at the time). Still, all in all it's been really good in comparison to btrfs.
I've been using btrfs as the primary FS for my laptop for nearly twenty years, and for my desktop and multipurpose box for as long as they've existed (~eight and ~three years, respectively). I haven't had troubles with the laptop FS in like fifteen years, and have never had troubles with the desktop or multipurpose box.
I also used btrfs as the production FS for the volume management in our CI at $DAYJOB, as it was way faster than overlayfs. No problems there, either.
Go figure, I guess.
man 8 integritysetup:
--integrity-bitmap-mode. -B
Use alternate bitmap mode (available since Linux kernel 5.2) where dm-integrity uses bitmap instead of a journal. If a bit in the bitmap is 1, then corresponding region’s data and integrity tags are not synchronized - if the machine crashes, the unsynchronized regions will be recalculated. The bitmap mode is faster than the journal mode, because we don’t have to write the data twice, but it is also less reliable, because if data corruption happens when the machine crashes, it may not be detected.
As I said -- boring tech. Just what I like when not in a mood to lose data.
RAID and logical block redundancy has scaled to petabytes for years in serious production use, before btrfs was even developed.
(50TB+ on ext4 and xfs, and no, no bit rot. Yes, I've checked most of it against separate sha256sum files now and then. As long as you have ECC RAM, disks just magically corrupting your data is largely a myth.)
Not particularly frequent either way, but I have absolutely had models of SSDs where it became clear after a few months of use that a significant fraction of them appeared to be corrupting their internal state and serving incorrect data back to the host, leading to errors and panics.
(_usually_ this was accompanied by read or write errors. But _usually_ is notable when you've spent some time trying to figure out if the times it didn't were a different problem or the same problem but silent.)
There was also the notorious case with certain Samsung spinning rust and dropping data in their write cache if you issued SMART requests...
I suspect this is still vulnerable to the write hole problem.
You can add LVM to get snapshots, but this still not an end-to-end copy-on-write solution that btrfs and ZFS should provide.