OpenZFS on Linux and FreeBSD
Go to file
Matthew Ahrens be89734a29 compress metadata in later sync passes
Starting in sync pass 5 (zfs_sync_pass_dont_compress), we disable
compression (including of metadata).  Ostensibly this helps the sync
passes to converge (i.e. for a sync pass to not need to allocate
anything because it is 100% overwrites).

However, in practice it increases the average number of sync passes,
because when we turn compression off, a lot of block's size will change
and thus we have to re-allocate (not overwrite) them.  It also increases
the number of 128KB allocations (e.g. for indirect blocks and spacemaps)
because these will not be compressed.  The 128K allocations are
especially detrimental to performance on highly fragmented systems,
which may have very few free segments of this size, and may need to load
new metaslabs to satisfy 128K allocations.

We should increase zfs_sync_pass_dont_compress.  In practice on a highly
fragmented system we see a few 5-pass txg's, a tiny number of 6-pass
txg's, and no txg's with more than 6 passes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-63431
Closes #8892
2019-06-13 13:10:18 -07:00
.github Update CONTRIBUTING to point users to IRC as well as mailing list 2019-03-13 11:57:57 -07:00
cmd make zil max block size tunable 2019-06-10 11:48:42 -07:00
config Allow TRIM_UNUSED_KSYM when build as a builtin-module 2019-06-04 18:12:16 -07:00
contrib If $ZFS_BOOTFS contains guid, replace the guid portion with $pool 2019-06-06 13:04:35 -07:00
etc Fix zfs-mount-generator for datasets with spaces 2019-05-07 09:32:23 -07:00
include Restrict filesystem creation if name referred either '.' or '..' 2019-06-13 08:56:15 -07:00
lib Restrict filesystem creation if name referred either '.' or '..' 2019-06-13 08:56:15 -07:00
man compress metadata in later sync passes 2019-06-13 13:10:18 -07:00
module compress metadata in later sync passes 2019-06-13 13:10:18 -07:00
rpm Add diffutils dependency for dkms build 2019-02-20 10:04:05 -08:00
scripts Fix %post and %postun generation in kmodtool 2019-06-10 09:06:58 -07:00
tests Restrict filesystem creation if name referred either '.' or '..' 2019-06-13 08:56:15 -07:00
udev Add enclosure_symlinks option to vdev_id 2018-12-14 17:27:49 -08:00
.gitignore git ignore python 3.7 virtual environment directories 2019-03-25 15:05:26 -07:00
.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
CODE_OF_CONDUCT.md Add CODE_OF_CONDUCT.md 2019-04-30 10:58:45 -07:00
COPYRIGHT Update build system and packaging 2018-05-29 16:00:33 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
META Tag 0.8.0 2019-05-21 11:11:41 -07:00
Makefile.am zfs-tests: fix warnings when packaging some .shlib files 2019-05-24 14:12:14 -07:00
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 Explicitly state supported Linux versions 2018-05-30 20:11:19 -07:00
TEST 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
configure.ac Add TRIM support 2019-03-29 09:13:20 -07:00
copy-builtin Allow copy-builtin to work with modified sources 2018-10-17 12:06:05 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.md

img

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.

codecov coverity

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.

Release

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.