mirror_zfs/module
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
..
avl Prefer VERIFY0P(n) over VERIFY(n == NULL) 2025-08-07 11:41:37 -07:00
icp Fix warnings about sha2_is_supported on FreeBSD/i386 2025-09-09 17:06:40 -07:00
lua SPDX: license tags: MIT 2025-03-13 17:56:54 -07:00
nvpair Prefer VERIFY0P(n) over VERIFY3P(n, ==, NULL) 2025-08-07 11:41:42 -07:00
os Enable zhack to work properly with 4k sector size disks 2025-09-10 15:01:32 -07:00
unicode SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
zcommon Detect a slow raidz child during reads 2025-09-10 15:31:30 -07:00
zfs Detect a slow raidz child during reads 2025-09-10 15:31:30 -07:00
zstd Silence zstd large allocation warning 2025-08-12 13:38:08 -07:00
.gitignore FreeBSD: Ignore symlink to i386 includes 2022-08-02 16:34:23 -07:00
Kbuild.in config: add and use KERNEL_CC check for -Wno-format-zero-length 2025-09-09 17:03:49 -07:00
Makefile.bsd Add TXG timestamp database 2025-08-06 10:31:21 -07:00
Makefile.in objtool wrapper: use absolute path to call the wrapper 2025-07-14 15:10:02 -07:00