Good Btrfs Feature Interactions

bees has been tested in combination with the following:

• btrfs compression (zlib, lzo, zstd)
• PREALLOC extents (unconditionally replaced with holes)
• HOLE extents and btrfs no-holes feature
• Other deduplicators (duperemove, jdupes)
• Reflink copies (modern coreutils cp and mv)
• Concurrent file modification (e.g. PostgreSQL and sqlite databases, VMs, build daemons)
• All btrfs RAID profiles: single, dup, raid0, raid1, raid10, raid1c3, raid1c4, raid5, raid6
• IO errors during dedupe (affected extents are skipped)
• 4K filesystem data block size / clone alignment
• 64-bit and 32-bit LE host CPUs (amd64, x86, arm)
• Large files (kernel 5.4 or later strongly recommended)
• Filesystem data sizes up to 100T+ bytes, 1000M+ files
• open(O_DIRECT) (seems to work as well–or as poorly–with bees as with any other btrfs feature)
• btrfs-convert from ext2/3/4
• btrfs autodefrag mount option
• btrfs balance (data balances cause rescan of relocated data)
• btrfs block-group-tree
• btrfs flushoncommit and noflushoncommit mount options
• btrfs mixed block groups
• btrfs nodatacow/nodatasum inode attribute or mount option (bees skips all nodatasum files)
• btrfs qgroups and quota support (not squotas)
• btrfs receive
• btrfs scrub
• btrfs send (dedupe pauses automatically, kernel 5.4 or later required)
• btrfs snapshot, non-snapshot subvols (RW and RO), snapshot delete

Note: some btrfs features have minimum kernel versions which are higher than the minimum kernel version for bees.

Untested Btrfs Feature Interactions

bees has not been tested with the following, and undesirable interactions may occur:

• Non-4K filesystem data block size (should work if recompiled)
• Non-equal hash (SUM) and filesystem data block (CLONE) sizes (need to fix that eventually)
• btrfs seed filesystems, raid-stripe-tree, squotas (no particular reason these wouldn’t work, but no one has reported trying)
• btrfs out-of-tree kernel patches (e.g. encryption, extent tree v2)
• Host CPUs with exotic page sizes, alignment requirements, or endianness (ppc, alpha, sparc, strongarm, s390, mips, m68k…)