Slow disk response times can be indicative of a failing drive. ZFS
currently tracks slow I/Os (slower than zio_slow_io_ms) and generates
events (ereport.fs.zfs.delay). However, no action is taken by ZED,
like is done for checksum or I/O errors. This change adds slow disk
diagnosis to ZED which is opt-in using new VDEV properties:
VDEV_PROP_SLOW_IO_N
VDEV_PROP_SLOW_IO_T
If multiple VDEVs in a pool are undergoing slow I/Os, then it skips
the zpool_vdev_degrade().
Sponsored-By: OpenDrives Inc.
Sponsored-By: Klara Inc.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Rob Wing <rob.wing@klarasystems.com>
Signed-off-by: Don Brady <don.brady@klarasystems.com>
Closes#15469
The phase 2 work primarily entails the Diagnosis Engine and
the Retire Agent modules. It also includes infrastructure
to support a crude FMD environment to host these modules.
The Diagnosis Engine consumes I/O and checksum ereports and
feeds them into a SERD engine which will generate a corres-
ponding fault diagnosis when the SERD engine fires. All the
diagnosis state data is collected into cases, one case per
vdev being tracked.
The Retire Agent responds to diagnosed faults by isolating
the faulty VDEV. It will notify the ZFS kernel module of
the new VDEV state (degraded or faulted). This agent is
also responsible for managing hot spares across pools.
When it encounters a device fault or a device removal it
replaces the device with an appropriate spare if available.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@intel.com>
Closes#5343
