Right now I have a pretty traditional backup filesystem structure on top of ext4. Every time a backup is made, a new folder
backup-DATE is created to which files are rsync'ed (with hardlinks made using rsync's
Since I have read about bitrot, I would like to have a checksum for all files, transparently. Apparently ext4 cannot do that, but btrfs does offer support for data checksums (and even a built-in RAID1 mode). For a start, I would like to use
btrfs as a "dumb" filesystem which supports data checksums without using its advanced features such as RAID, subvolume snapshots, send/receive, etc.
However, their wiki do not really inspire confidence in the filesystem for backups purposes:
"While many people use it reliably, there are still problems being found. You should keep and test backups of your data, and be prepared to use them." - Getting Started
"Is btrfs stable? Long answer: [..] Whatever you do, we recommend keeping good, tested, off-system (and off-site) backups." - FAQ.
My use case is to have an offline backup. For that reason the disk will see very little use (as in hours) and will be frequently plugged/unplugged (eSATA or USB 3.0). Having a reliable filesystem is a must. It must not be worse than ext4 wrt. power failures, unclean shutdowns, etc.
Is it actually recommended to use btrfs as filesystem for backup purposes? Are there other properties of btrfs which may make it less (or more) suitable?