BORG-COMPRESSION(1) | borg backup tool | BORG-COMPRESSION(1) |
borg-compression - Details regarding compression
It is no problem to mix different compression methods in one repo, deduplication is done on the source data chunks (not on the compressed or encrypted data).
If some specific chunk was once compressed and stored into the repo, creating another backup that also uses this chunk will not change the stored chunk. So if you use different compression specs for the backups, whichever stores a chunk first determines its compression. See also borg recreate.
Compression is lz4 by default. If you want something else, you have to specify what you want.
Valid compression specifiers are:
The SPEC value will determine how the size obfuscation will work:
Relative random reciprocal size variation: Size will increase by a factor, relative to the compressed data size. Smaller factors are often used, larger factors rarely. 1: factor 0.01 .. 100.0 2: factor 0.1 .. 1000.0 3: factor 1.0 .. 10000.0 4: factor 10.0 .. 100000.0 5: factor 100.0 .. 1000000.0 6: factor 1000.0 .. 10000000.0
Add a randomly sized padding up to the given size: 110: 1kiB ... 120: 1MiB ... 123: 8MiB (max.)
Examples:
borg create --compression lz4 REPO::ARCHIVE data borg create --compression zstd REPO::ARCHIVE data borg create --compression zstd,10 REPO::ARCHIVE data borg create --compression zlib REPO::ARCHIVE data borg create --compression zlib,1 REPO::ARCHIVE data borg create --compression auto,lzma,6 REPO::ARCHIVE data borg create --compression auto,lzma ... borg create --compression obfuscate,3,none ... borg create --compression obfuscate,3,auto,zstd,10 ... borg create --compression obfuscate,2,zstd,6 ...
The Borg Collective
2023-03-22 |