zfs/include/os/freebsd
Paul Dagnelie df55ba7c49 Detect a slow raidz child during reads
A single slow responding disk can affect the overall read
performance of a raidz group.  When a raidz child disk is
determined to be a persistent slow outlier, then have it
sit out during reads for a period of time. The raidz group
can use parity to reconstruct the data that was skipped.

Each time a slow disk is placed into a sit out period, its
`vdev_stat.vs_slow_ios count` is incremented and a zevent
class `ereport.fs.zfs.delay` is posted.

The length of the sit out period can be changed using the
`raid_read_sit_out_secs` module parameter.  Setting it to
zero disables slow outlier detection.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <paul.dagnelie@klarasystems.com>
Contributions-by: Don Brady <don.brady@klarasystems.com>
Contributions-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #17227
2025-09-10 15:31:30 -07:00
..
linux SPDX: license tags: BSD-2-Clause 2025-03-13 17:56:46 -07:00
spl Detect a slow raidz child during reads 2025-09-10 15:31:30 -07:00
zfs/sys Add default user/group/project quota properties 2025-04-03 10:35:22 -07:00
Makefile.am mod.h: make consistent across all three platforms 2025-07-15 15:46:14 -07:00