mirror_zfs/man
Alexander Motin 70ea484e3e
Finally drop long disabled vdev cache.
It was a vdev level read cache, designed to aggregate many small
reads by speculatively issuing bigger reads instead and caching
the result.  But since it has almost no idea about what is going
on with exception of ZIO_FLAG_DONT_CACHE flag set by higher layers,
it was found to make more harm than good, for which reason it was
disabled for the past 12 years.  These days we have much better
instruments to enlarge the I/Os, such as speculative and prescient
prefetches, I/O scheduler, I/O aggregation etc.

Besides just the dead code removal this removes one extra mutex
lock/unlock per write inside vdev_cache_write(), not otherwise
disabled and trying to do some work.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #14953
2023-06-09 12:40:55 -07:00
..
man1 Allow zhack label repair to restore detached devices. 2023-05-03 09:03:57 -07:00
man4 Finally drop long disabled vdev cache. 2023-06-09 12:40:55 -07:00
man5 Consistentify miscellaneous style on remaining manpages 2021-06-09 14:35:53 -07:00
man7 Adding new read-only compatible zpool features to compatibility.d/grub2 2023-05-26 10:04:19 -07:00
man8 Finally drop long disabled vdev cache. 2023-06-09 12:40:55 -07:00
Makefile.am Add vdevprops.7 to the Makefile 2023-02-27 16:38:09 -08:00