0f740a4f1d
Despite all optimizations, tests on actual hardware show that FreeBSD kernel can't sleep for less then ~2us. Similar tests on Linux show ~50us delay at least from nanosleep() (haven't tested inside kernel). It means that on very fast log device ZIL may not be able to satisfy zfs_commit_timeout_pct block commit timeout, increasing log latency more than desired. Handle that by introduction of zil_min_commit_timeout parameter, specifying minimal timeout value where additional delays to aggregate writes may be skipped. Also skip delays if the LWB is more than 7/8 full, that often happens if I/O sizes are constant and match one of LWB sizes. Both things are applied only if there were no already outstanding log blocks, that may indicate single-threaded workload, that by definition can not benefit from the commit delays. While there, add short time moving average to zl_last_lwb_latency to make it more stable. Tests of single-threaded 4KB writes to NVDIMM SLOG on FreeBSD show IOPS increase by 9% instead of expected 5%. For zfs_commit_timeout_pct of 1 there IOPS increase by 5.5% instead of expected 1%. Reviewed-by: Allan Jude <allan@klarasystems.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Prakash Surya <prakash.surya@delphix.com> Signed-off-by: Alexander Motin <mav@FreeBSD.org> Sponsored by: iXsystems, Inc. Closes #14418
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
- The
METAfile contains the officially recognized supported Linux kernel versions. - Supported FreeBSD versions are any supported branches and releases starting from 12.2-RELEASE.