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Alexander Motin 37f6845c6f
Improve too large physical ashift handling
When iterating through children physical ashifts for vdev, prefer
ones above the maximum logical ashift, that we can actually use,
but within the administrator defined maximum.

When selecting top-level vdev ashift, do not set it to the defined
maximum in case physical ashift is even higher, but just ignore one.
Using the maximum does not prevent misaligned writes, but reduces
space efficiency.  Since ZFS tries to write data sequentially and
aggregates the writes, in many cases large misanigned writes may be
not as bad as the space penalty otherwise.

Allow internal physical ashifts for vdevs higher than SHIFT_MAX.
May be one day allocator or aggregation could benefit from that.

Reduce zfs_vdev_max_auto_ashift default from 16 (64KB) to 14 (16KB),
so that ZFS may still use bigger ashifts up to SHIFT_MAX (64KB),
but only if it really has to or explicitly told to, but not as an
"optimization".

There are some read-intensive NVMe SSDs that report Preferred Write
Alignment of 64KB, and attempt to build RAIDZ2 of those leads to a
space inefficiency that can't be justified.  Instead these changes
make ZFS fall back to logical ashift of 12 (4KB) by default and
only warn user that it may be suboptimal for performance.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #13798
2022-09-08 10:30:53 -07:00
.github Replace EXTRA_DIST with dist_noinst_DATA 2022-05-26 09:24:50 -07:00
cmd Fix column width in 'zpool iostat -v' and 'zpool list -v' 2022-09-06 09:37:47 -07:00
config Add Linux posix_fadvise support 2022-09-08 10:29:41 -07:00
contrib contrib: dracut: zfs-snapshot-bootfs: exit status fix 2022-08-12 14:28:15 -07:00
etc Enable -Wwrite-strings 2022-06-29 14:08:54 -07:00
include Improve too large physical ashift handling 2022-09-08 10:30:53 -07:00
lib Importing from cachefile can trip assertion 2022-08-26 14:04:27 -07:00
man Improve too large physical ashift handling 2022-09-08 10:30:53 -07:00
module Improve too large physical ashift handling 2022-09-08 10:30:53 -07:00
rpm Add zilstat script to report zil kstats in a user friendly manner 2022-09-02 13:24:07 -07:00
scripts Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
tests Improve too large physical ashift handling 2022-09-08 10:30:53 -07:00
udev Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore autoconf: use include directives instead of recursing down cmd 2022-05-10 10:18:38 -07:00
.gitmodules .gitmodules: link to openzfs github repository 2021-04-12 09:37:23 -07:00
AUTHORS Introduce BLAKE3 checksums as an OpenZFS feature 2022-06-08 15:55:57 -07:00
autogen.sh autogen.sh: paper over automake <1.14's lack of %reldir% support 2022-05-10 10:20:46 -07:00
CODE_OF_CONDUCT.md Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
configure.ac Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
copy-builtin copy-builtin: add hooks with sed/>> 2022-05-10 10:17:43 -07:00
COPYRIGHT Fix typos 2020-06-09 21:24:09 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
Makefile.am Replace EXTRA_DIST with dist_noinst_DATA 2022-05-26 09:24:50 -07:00
META Linux 5.19 compat: META 2022-08-02 10:04:38 -07:00
NEWS Fix NEWS file 2020-08-26 21:44:41 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md README: Update OpenZFS website url 2022-01-06 16:25:01 -08:00
RELEASES.md Add RELEASES.md file 2021-04-02 16:33:40 -07:00
TEST Remove CI builder customization from TEST 2020-03-16 10:46:03 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

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OpenZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community. This repository contains the code for running OpenZFS on Linux and FreeBSD.

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Official Resources

Installation

Full documentation for installing OpenZFS on your favorite operating system can be found at the Getting Started Page.

Contribute & Develop

We have a separate document with contribution guidelines.

We have a Code of Conduct.

Release

OpenZFS 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 Linux kernel versions.
  • Supported FreeBSD versions are any supported branches and releases starting from 12.2-RELEASE.