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Matthew Ahrens 4fe3a842bb
Remove limit on number of async zio_frees of non-dedup blocks
The module parameter zfs_async_block_max_blocks limits the number of
blocks that can be freed by the background freeing of filesystems and
snapshots (from "zfs destroy"), in one TXG.  This is useful when freeing
dedup blocks, becuase each zio_free() of a dedup block can require an
i/o to read the relevant part of the dedup table (DDT), and will also
dirty that block.

zfs_async_block_max_blocks is set to 100,000 by default.  For the more
typical case where dedup is not used, this can have a negative
performance impact on the rate of background freeing (from "zfs
destroy").  For example, with recordsize=8k, and TXG's syncing once
every 5 seconds, we can free only 160MB of data per second, which may be
much less than the rate we can write data.

This change increases zfs_async_block_max_blocks to be unlimited by
default.  To address the dedup freeing issue, a new tunable is
introduced, zfs_max_async_dedup_frees, which limits the number of
zio_free()'s of dedup blocks done by background destroys, per txg.  The
default is 100,000 free's (same as the old zfs_async_block_max_blocks
default).

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10000
2020-02-14 08:39:46 -08:00
.github Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
cmd Make zpool.d/iostat work on FreeBSD 2020-02-14 08:37:40 -08:00
config Use POSIX stdout/stderr redirect in configure macro 2020-02-14 08:30:29 -08:00
contrib Implement bookmark copying 2020-02-11 13:19:12 -08:00
etc zfs-mount-generator: Fix escaping for / 2020-02-13 11:55:59 -08:00
include Remove limit on number of async zio_frees of non-dedup blocks 2020-02-14 08:39:46 -08:00
lib Move zfs_version_kernel to platform code 2020-02-12 13:00:19 -08:00
man Remove limit on number of async zio_frees of non-dedup blocks 2020-02-14 08:39:46 -08:00
module Remove limit on number of async zio_frees of non-dedup blocks 2020-02-14 08:39:46 -08:00
rpm Change http://zfsonlinux.org links to https://zfsonlinux.org 2020-01-13 16:43:59 -08:00
scripts bash scripts: use /usr/bin/env for bash shebangs 2020-02-10 13:13:46 -08:00
tests ZTS: Misc test fixes for FreeBSD 2020-02-13 13:52:34 -08:00
udev Create symbolic links in /dev/disk/by-vdev for nvme disk devices 2019-12-17 17:50:20 -08:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore Adapt gitignore for modules 2019-12-02 13:23:47 -08:00
.gitmodules Add zimport.sh compatibility test script 2014-02-21 12:10:31 -08:00
.travis.yml Add .travis.yml 2017-11-13 09:18:18 -08:00
AUTHORS Update build system and packaging 2018-05-29 16:00:33 -07:00
autogen.sh Cause autogen.sh to fail if autoreconf fails 2018-07-06 09:27:37 -07:00
CODE_OF_CONDUCT.md Add CODE_OF_CONDUCT.md 2019-04-30 10:58:45 -07:00
configure.ac Tests for btree implementation used by range trees 2019-12-19 11:53:54 -08:00
copy-builtin bash scripts: use /usr/bin/env for bash shebangs 2020-02-10 13:13:46 -08:00
COPYRIGHT ICP: Improve AES-GCM performance 2020-02-10 12:59:50 -08:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
Makefile.am Perform KABI checks in parallel 2019-10-01 12:50:34 -07:00
META Update maximum kernel version to 5.4 2019-12-23 14:24:36 -08:00
NEWS Add NEWS file 2018-09-18 12:03:47 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md Change http://zfsonlinux.org links to https://zfsonlinux.org 2020-01-13 16:43:59 -08:00
TEST Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

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ZFS on Linux is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community.

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Official Resources

Installation

Full documentation for installing ZoL on your favorite Linux distribution can be found at our site.

Contribute & Develop

We have a separate document with contribution guidelines.

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ZFS on Linux is released under a CDDL license.
For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported kernel versions.