snapraid-btrfs VS btrfs-progs

Check out: https://github.com/automorphism88/snapraid-btrfs

I've been looking into snapraid-btrfs and snapraid-btrfs-runner.

- Use https://github.com/automorphism88/snapraid-btrfs which allows me to run 'snapraid' sync from a brtfs-snaptshot so the system can continue running 24/7 while doing parity maintenance tasks.

Add btrfs into the mix with snapraid-btrfs and now you have atomic snapshots and don't have to worry about new writes corrupting your snapshot data for that missing drive. And then automate it with snapraid-btrfs-runner, which will automatically check if more than X files were deleted, run the sync, run a scrub, and email you the result. After all that I use Borg Backup to backup content I generate (stuff I can't just download again) to a PC I have at my dad's house off-site. Which has already come in handy when a logical volume for my container data destroyed itself for some unknown reason (that was data on a RAID1 baked LVM volume with XFS as the filesystem).

Btrfs for data and ext4 for parity is one decent combination (btrfs should be absolutely safe enough on single drives) and you can also use something like https://github.com/automorphism88/snapraid-btrfs (read the FAQ if you're wondering why).

Not an answer to your question, but just making sure you are aware of this project: https://github.com/automorphism88/snapraid-btrfs

This is a cross-post from SnapRAID-BTRFS Github issue.

Because I need snapshots and I plan to use snapraid-btrfs.

Not an error I've seen before or that makes much sense to me at first glance, might want to take this to https://github.com/kdave/btrfs-progs/issues or the mailing list?

You can test it by allocating the space to see if it can use it all: e.g. fallocate -l 3.8t /mnt/elfstone2/butts should succeed. If it does, then it's probably fine even if the balance didn't do what it should have. If not and you run out of space with some unallocated space left on only one device, not so much. If its the same bug I saw that means if your fs was created pre kernel 5.19, it will not allocate correctly on >5.19 until the array is rebuilt under the newer kernel.

Mount options should be documented either at https://btrfs.readthedocs.io/en/latest/Administration.html or at the manual page section 5 (man 5 btrfs). Autodefrag is in section https://btrfs.readthedocs.io/en/latest/Administration.html#btrfs-specific-mount-options . In case you find more information missing, unclear, lacking cross-references please open an issue at https://github.com/kdave/btrfs-progs/issues .

thanks. I filled a feature request... https://github.com/kdave/btrfs-progs/issues/610

Resume sort of doesn't work, when you resumed it will have started a fresh balance with a high usage value (check your syslog to confirm).

That's the hint. It's an unfixed bug with the accounting when scrub is paused and resumed, the relevant issue is I think https://github.com/kdave/btrfs-progs/issues/227 .

[1] - https://github.com/kdave/btrfs-progs/issues/277

Hoping for a filesystem clone option at some point.