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.

• --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.

• --throttle-factor FACTOR

In order to avoid saturating btrfs deferred work queues, bees tracks the time that operations with delayed effect (dedupe and tmpfile copy) and operations with long run times (LOGICAL_INO) run. If an operation finishes before the average run time for that operation, bees will sleep for the remainder of the average run time, so that operations are submitted to btrfs at a rate similar to the rate that btrfs can complete them.

The FACTOR is multiplied by the average run time for each operation to calculate the target delay time.

FACTOR 0 is the default, which adds no delays. bees will attempt to saturate btrfs delayed work queues as quickly as possible, which may impact other processes on the same filesystem, or even slow down bees itself.

FACTOR 1.0 will attempt to keep btrfs delayed work queues filled at a steady average rate.

FACTOR more than 1.0 will add delays longer than the average run time (e.g. 10.0 will delay all operations that take less than 10x the average run time). High values of FACTOR may be desirable when using bees with other applications on the same filesystem.

The maximum delay per operation is 60 seconds.

Filesystem tree traversal options

• --scan-mode MODE or -m

Specify extent scanning algorithm. EXPERIMENTAL feature that may go away.

• Mode 0: lockstep
• Mode 1: independent
• Mode 2: sequential
• Mode 3: recent
• Mode 4: extent

For details of the different scanning modes and the default value of this option, see bees configuration.

Workarounds

• --workaround-btrfs-send or -a

This option is obsolete and should not be used any more.

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 old kernels running btrfs send and btrfs send -p which make these btrfs features unusable with bees.

This option was used to avoid breaking btrfs send on old kernels. The affected kernels are now too old to be recommended for use with bees.

bees now waits for btrfs send to finish. There is no need for an option to enable this.

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.

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).