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bees Command Line Options

Load management options

  • --thread-count COUNT or -c

Specify maximum number of worker threads. Overrides --thread-factor (-C), default/autodetected values, and the hardcoded thread limit.

  • --thread-factor FACTOR or -C

Specify ratio of worker threads to detected CPU cores. Overridden by --thread-count (-c).

Default is 1.0, i.e. 1 worker thread per detected CPU. Use values below 1.0 to leave some cores idle, or above 1.0 if there are more disks than CPUs in the filesystem.

If the computed thread count is higher than BEES_DEFAULT_THREAD_LIMIT (currently 8), then only that number of threads will be created. This limit can be overridden by the --thread-count option; however, be aware that there are kernel issues with systems that have many CPU cores when users try to run bees on all of them.

  • --loadavg-target LOADAVG or -g

Specify load average target for dynamic worker threads. Default is to run the maximum number of worker threads all the time.

Worker threads will be started or stopped subject to the upper limit imposed by --thread-factor, --thread-min and --thread-count until the load average is within +/- 0.5 of LOADAVG.

  • --thread-min COUNT or -G

Specify minimum number of dynamic worker threads. This can be used to force a minimum number of threads to continue running while using --loadavg-target to manage load.

Default is 0, i.e. all bees worker threads will stop when the system load exceeds the target.

Has no effect unless --loadavg-target is used to specify a target load.

Filesystem tree traversal options

  • --scan-mode MODE or -m

Specify extent scanning algorithm. Default MODE is 0. EXPERIMENTAL feature that may go away.

  • Mode 0: scan extents in ascending order of (inode, subvol, offset). Keeps shared extents between snapshots together. Reads files sequentially. Minimizes temporary space usage.
  • Mode 1: scan extents from all subvols in parallel. Good performance on non-spinning media when subvols are unrelated.
  • Mode 2: scan all extents from one subvol at a time. Good sequential read performance for spinning media. Maximizes temporary space usage.

Workarounds

  • --workaround-btrfs-send or -a

Pretend that read-only snapshots are empty and silently discard any request to dedupe files referenced through them. This is a workaround for problems with the kernel implementation of btrfs send and btrfs send -p which make these btrfs features unusable with bees.

This option should be used to avoid breaking btrfs send on the same filesystem.

Note: There is a significant space tradeoff when using this option: it is likely no space will be recovered--and possibly significant extra space used--until the read-only snapshots are deleted. On the other hand, if snapshots are rotated frequently then bees will spend less time scanning them.

Logging options

  • --timestamps or -t

Enable timestamps in log output.

  • --no-timestamps or -T

Disable timestamps in log output.

  • --absolute-paths or -p

Paths in log output will be absolute.

  • --strip-paths or -P

Paths in log output will have the working directory at bees startup stripped.

  • --verbose or -v

Set log verbosity (0 = no output, 8 = all output, default 8).