mirror_zfs/module/zcommon
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
..
cityhash.c SPDX: license tags: MIT 2025-03-13 17:56:54 -07:00
simd_stat.c simd_stat: expose availability of VAES and VPCLMULQDQ 2025-08-13 14:53:24 -07:00
zfeature_common.c Implement physical rewrites 2025-08-06 10:36:56 -07:00
zfs_comutil.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zfs_deleg.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zfs_fletcher_aarch64_neon.c SPDX: license tags: BSD-2-Clause OR GPL-2.0-only 2025-03-13 17:57:21 -07:00
zfs_fletcher_avx512.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zfs_fletcher_intel.c SPDX: license tags: BSD-2-Clause OR GPL-2.0-only 2025-03-13 17:57:21 -07:00
zfs_fletcher_sse.c SPDX: license tags: BSD-2-Clause OR GPL-2.0-only 2025-03-13 17:57:21 -07:00
zfs_fletcher_superscalar4.c SPDX: license tags: BSD-2-Clause OR GPL-2.0-only 2025-03-13 17:57:21 -07:00
zfs_fletcher_superscalar.c SPDX: license tags: BSD-2-Clause OR GPL-2.0-only 2025-03-13 17:57:21 -07:00
zfs_fletcher.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zfs_namecheck.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zfs_prop.c Relax special_small_blocks restrictions 2025-07-02 11:11:37 -07:00
zfs_valstr.c metaslab: don't pass whole zio to throttle reserve APIs 2025-07-04 23:22:22 -04:00
zpool_prop.c Detect a slow raidz child during reads 2025-09-10 15:31:30 -07:00
zprop_common.c SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00