borg benchmark crud

borg [common options] benchmark crud [options] PATH

positional arguments

PATH

path where to create benchmark input data

options

--json-lines

Format output as JSON Lines.

Common options

Description

This command benchmarks borg CRUD (create, read, update, delete) operations.

It creates input data below the given PATH and backs up this data into the given REPO. The REPO must already exist (it could be a fresh empty repo or an existing repo, the command will create / read / update / delete some archives named borg-benchmark-crud* there.

Make sure you have free space there; you will need about 1 GB each (+ overhead).

If your repository is encrypted and borg needs a passphrase to unlock the key, use:

BORG_PASSPHRASE=mysecret borg benchmark crud REPO PATH

Measurements are done with different input file sizes and counts. The file contents are very artificial (either all zero or all random), thus the measurement results do not necessarily reflect performance with real data. Also, due to the kind of content used, no compression is used in these benchmarks.

C- == borg create (1st archive creation, no compression, do not use files cache)

C-Z- == all-zero files. full dedup, this is primarily measuring reader/chunker/hasher. C-R- == random files. no dedup, measuring throughput through all processing stages.

R- == borg extract (extract archive, dry-run, do everything, but do not write files to disk)

R-Z- == all zero files. Measuring heavily duplicated files. R-R- == random files. No duplication here, measuring throughput through all processing stages, except writing to disk.

U- == borg create (2nd archive creation of unchanged input files, measure files cache speed)

The throughput value is kind of virtual here, it does not actually read the file. U-Z- == needs to check the 2 all-zero chunks’ existence in the repo. U-R- == needs to check existence of a lot of different chunks in the repo.

D- == borg delete archive (delete last remaining archive, measure deletion + compaction)

D-Z- == few chunks to delete / few segments to compact/remove. D-R- == many chunks to delete / many segments to compact/remove.

Please note that there might be quite some variance in these measurements. Try multiple measurements and having a otherwise idle machine (and network, if you use it).

borg benchmark cpu

borg [common options] benchmark cpu [options]

options

--json

format output as JSON

--chunking

benchmark the chunkers

--hashing

benchmark the hashes / MACs

--encrypting

benchmark the encryption modes

--compressing

benchmark the compressors

--msgpacking

benchmark msgpack item packing

Common options

Description

This command benchmarks miscellaneous CPU-bound Borg operations.

It creates input data in memory, runs the operation and then displays throughput. To reduce outside influence on the timings, please make sure to run this with:

  • an otherwise as idle as possible machine

  • enough free memory so there will be no slow down due to paging activity

By default all benchmarks run. Give one or more of --chunking, --hashing, --encrypting, --compressing, --msgpacking to run only those.

Some algorithms use multiple threads only above a size threshold, so the hashes and the compressors are measured at more than one buffer size: the hashes at 64MiB (a borg pack) and 2MiB (a typical borg chunk), both above blake3’s threshold, the compressors at 2MiB and 128kiB, which is below zstd’s. Within a section every row processes the same total number of bytes - 1 GiB, or 10 MiB for the compressors - so the throughput column is comparable between rows.

The compressors work on synthetic text-like data that compresses about 4x at zstd,3. Random data would be the worst possible input: no codec can compress it, so all of them would take their incompressible fast path and the levels would barely differ.