Some of our random write benchmarks on a fragmented pool show that single-threaded portion of sync process (txg_sync_thread) can use up to 45% of CPU time. Most of it is consumed by metaslab_sync() and metaslab_sync_done(), during which time the pool is not doing anything else. While metaslab_sync() is not trivial to parallelize due to having single spacemap log, metaslab_sync_done() is doing only per-metaslab accounting and they can run in parallel. Even better, we can run them while waiting for vdev label update and cache flush I/Os. With this patch on my test system similar test randomly writing 12 100GB files with 4KB blocks shows IOPS increase from 176K to 220K. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com> Closes #18622
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.
Official Resources
- Documentation - for using and developing this repo
- ZoL site - Linux release info & links
- Mailing lists
- OpenZFS site - for conference videos and info on other platforms (illumos, OSX, Windows, etc)
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 and Distributions
Linux
Given the wide variety of Linux environments, we prioritize development and testing on stable, supported kernels and distributions.
Kernel (kernel.org)
All longterm kernels from kernel.org are supported. stable kernels are usually supported in the next OpenZFS release.
Supported longterm kernels: 6.18, 6.12, 6.6, 6.1, 5.15, 5.10.
Red Hat Enterprise Linux (RHEL)
All RHEL (and compatible systems: AlmaLinux OS, Rocky Linux, etc) on the full or maintenance support tracks are supported.
Supported RHEL releases: 8.10, 9.7, 10.1.
Ubuntu
All Ubuntu LTS releases are supported.
Supported Ubuntu releases: 26.04 “Resolute”, 24.04 “Noble”, 22.04 “Jammy”.
Debian
All Debian stable and LTS releases are supported.
Supported Debian releases: 13 “Trixie”, 12 “Bookworm”, 11 “Bullseye”.
Other Distributions
Generally, if a distribution is following an LTS kernel, it should work well with OpenZFS.
FreeBSD
All FreeBSD releases receiving security support are supported by OpenZFS.
Supported FreeBSD releases: 15.0, 14.4.
