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mirror of https://github.com/Zygo/bees.git synced 2025-05-17 13:25:45 +02:00
Zygo Blaxell 4021dd42ca task: queue and run exactly once per instance
Enable much simpler Task management:  each time a Task needs to be done
at least once in the future, simply invoke the run() method on the Task.
The Task will ensure that it only runs once, only appears in a queue
once, and will run again if a run request is made while the Task is
already running.

Make the queue policy a member of the Task rather than a method.  This
enables Tasks to reschedule themselves, possibly on the appropriate queue
if we have more than one of those some day.

This happens to make Tasks more similar to Linux kernel workers.
This similarity is coincidental, but not undesirable.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
2019-01-07 22:48:15 -05:00
2016-11-17 12:12:15 -05:00
2018-12-10 19:56:08 -05:00

BEES

Best-Effort Extent-Same, a btrfs deduplication agent.

About bees

bees is a block-oriented userspace deduplication agent designed for large btrfs filesystems. It is an offline dedupe combined with an incremental data scan capability to minimize time data spends on disk from write to dedupe.

Strengths

  • Space-efficient hash table and matching algorithms - can use as little as 1 GB hash table per 10 TB unique data (0.1GB/TB)
  • Daemon incrementally dedupes new data using btrfs tree search
  • Works with btrfs compression - dedupe any combination of compressed and uncompressed files
  • NEW Works around btrfs send problems with dedupe and incremental parent shapshots
  • Works around btrfs filesystem structure to free more disk space
  • Persistent hash table for rapid restart after shutdown
  • Whole-filesystem dedupe - including snapshots
  • Constant hash table size - no increased RAM usage if data set becomes larger
  • Works on live data - no scheduled downtime required
  • Automatic self-throttling based on system load

Weaknesses

  • Whole-filesystem dedupe - has no include/exclude filters, does not accept file lists
  • Requires root privilege (or CAP_SYS_ADMIN)
  • First run may require temporary disk space for extent reorganization
  • First run may increase metadata space usage if many snapshots exist
  • Constant hash table size - no decreased RAM usage if data set becomes smaller
  • btrfs only

Installation and Usage

More Information

Bug Reports and Contributions

Email bug reports and patches to Zygo Blaxell bees@furryterror.org.

You can also use Github:

    https://github.com/Zygo/bees

Copyright 2015-2018 Zygo Blaxell bees@furryterror.org.

GPL (version 3 or later).

Description
Best-Effort Extent-Same, a btrfs dedupe agent
Readme 1.7 MiB
Languages
C++ 97%
C 1.6%
Makefile 0.8%
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