Even the much-maligned raid5/6 is basically fine†.
If you're concerned about the write hole, use -m DUP/raid1/raid1c2 instead of -m raid5. Plus raid-stripe-tree†† is coming - didn't check the status of it recently.
Many horror stories are because, while btrfs is fine, the operational model and tooling have some footguns which can cause either straight up data loss (due to operator error, but arguably that's really due to bad UX) or possible-but-hard-to-get-out-of situations.
I use btrfs because using zfs has been painful for me, for two reasons:
- btrfs can "shapeshift": I progressively moved _live_ from 2hdd raid1 to 5hdd raid5 data + raid1c2 meta with varying experiments in between. Probably five or six rebalance to change its shape over the years.
- the zfs module situation: when I tried it, the module silently failed to build properly and this resulted in a broken system til I fixed it; this happened twice over six months. Luckily I anticipated this failure mode and only the data array (not the root fs) was zfs, so I could still boot and login into a full system to fix.
Compared to zfs, btrfs is slow to scrub and rebalance though.
If you're concerned about the write hole, use -m DUP/raid1/raid1c2 instead of -m raid5. Plus raid-stripe-tree†† is coming - didn't check the status of it recently.
Many horror stories are because, while btrfs is fine, the operational model and tooling have some footguns which can cause either straight up data loss (due to operator error, but arguably that's really due to bad UX) or possible-but-hard-to-get-out-of situations.
I use btrfs because using zfs has been painful for me, for two reasons:
- btrfs can "shapeshift": I progressively moved _live_ from 2hdd raid1 to 5hdd raid5 data + raid1c2 meta with varying experiments in between. Probably five or six rebalance to change its shape over the years.
- the zfs module situation: when I tried it, the module silently failed to build properly and this resulted in a broken system til I fixed it; this happened twice over six months. Luckily I anticipated this failure mode and only the data array (not the root fs) was zfs, so I could still boot and login into a full system to fix.
Compared to zfs, btrfs is slow to scrub and rebalance though.
† https://unixdigest.com/articles/battle-testing-zfs-btrfs-and...
†† https://lore.kernel.org/linux-btrfs/cover.1698679287.git.dst...