mirror_zfs/man
Brian Behlendorf 6b95031f56
zed: Add deadman-slot_off.sh zedlet
Optionally turn off disk's enclosure slot if an I/O is hung
triggering the deadman.

It's possible for outstanding I/O to a misbehaving SCSI disk to
neither promptly complete or return an error.  This can occur due
to retry and recovery actions taken by the SCSI layer, driver, or
disk.  When it occurs the pool will be unresponsive even though
there may be sufficient redundancy configured to proceeded without
this single disk.

When a hung I/O is detected by the kmods it will be posted as a
deadman event.  By default an I/O is considered to be hung after
5 minutes.  This value can be changed with the zfs_deadman_ziotime_ms
module parameter.  If ZED_POWER_OFF_ENCLOSURE_SLOT_ON_DEADMAN is set
the disk's enclosure slot will be powered off causing the outstanding
I/O to fail.  The ZED will then handle this like a normal disk failure.
By default ZED_POWER_OFF_ENCLOSURE_SLOT_ON_DEADMAN is not set.

As part of this change `zfs_deadman_events_per_second` is added
to control the ratelimitting of deadman events independantly of
delay events.  In practice, a single deadman event is sufficient
and more aren't particularly useful.

Alphabetize the zfs_deadman_* entries in zfs.4.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #16226
2024-05-29 10:46:41 -07:00
..
man1 RAID-Z expansion feature 2023-11-08 10:19:41 -08:00
man4 zed: Add deadman-slot_off.sh zedlet 2024-05-29 10:46:41 -07:00
man5 Consistentify miscellaneous style on remaining manpages 2021-06-09 14:35:53 -07:00
man7 vdev props comment and manpage should include zfsd and FreeBSD mentions 2024-04-03 17:56:34 -07:00
man8 vdev probe to slow disk can stall mmp write checker 2024-04-29 14:35:53 -07:00
Makefile.am man: move zfs_prepare_disk.8 to nodist_man_MANS 2024-04-03 18:04:15 -07:00