Provided by: zfsutils-linux_2.1.5-1ubuntu6~22.04.4_amd64 
NAME
zpool-events — list recent events generated by kernel
SYNOPSIS
zpool events [-vHf] [pool]
zpool events -c
DESCRIPTION
Lists all recent events generated by the ZFS kernel modules. These events are consumed by
the zed(8) and used to automate administrative tasks such as replacing a failed device with
a hot spare. For more information about the subclasses and event payloads that can be
generated see EVENTS and the following sections.
OPTIONS
-c Clear all previous events.
-f Follow mode.
-H Scripted mode. Do not display headers, and separate fields by a single tab instead
of arbitrary space.
-v Print the entire payload for each event.
EVENTS
These are the different event subclasses. The full event name would be
ereport.fs.zfs.SUBCLASS, but only the last part is listed here.
checksum Issued when a checksum error has been detected.
io Issued when there is an I/O error in a vdev in the pool.
data Issued when there have been data errors in the pool.
deadman Issued when an I/O request is determined to be "hung", this can be caused
by lost completion events due to flaky hardware or drivers. See
zfs_deadman_failmode in zfs(4) for additional information regarding
"hung" I/O detection and configuration.
delay Issued when a completed I/O request exceeds the maximum allowed time
specified by the zio_slow_io_ms module parameter. This can be an
indicator of problems with the underlying storage device. The number of
delay events is ratelimited by the zfs_slow_io_events_per_second module
parameter.
config Issued every time a vdev change have been done to the pool.
zpool Issued when a pool cannot be imported.
zpool.destroy Issued when a pool is destroyed.
zpool.export Issued when a pool is exported.
zpool.import Issued when a pool is imported.
zpool.reguid Issued when a REGUID (new unique identifier for the pool have been
regenerated) have been detected.
vdev.unknown Issued when the vdev is unknown. Such as trying to clear device errors
on a vdev that have failed/been kicked from the system/pool and is no
longer available.
vdev.open_failed Issued when a vdev could not be opened (because it didn't exist for
example).
vdev.corrupt_data Issued when corrupt data have been detected on a vdev.
vdev.no_replicas Issued when there are no more replicas to sustain the pool. This would
lead to the pool being DEGRADED.
vdev.bad_guid_sum Issued when a missing device in the pool have been detected.
vdev.too_small Issued when the system (kernel) have removed a device, and ZFS notices
that the device isn't there any more. This is usually followed by a
probe_failure event.
vdev.bad_label Issued when the label is OK but invalid.
vdev.bad_ashift Issued when the ashift alignment requirement has increased.
vdev.remove Issued when a vdev is detached from a mirror (or a spare detached from a
vdev where it have been used to replace a failed drive - only works if
the original drive have been re-added).
vdev.clear Issued when clearing device errors in a pool. Such as running zpool
clear on a device in the pool.
vdev.check Issued when a check to see if a given vdev could be opened is started.
vdev.spare Issued when a spare have kicked in to replace a failed device.
vdev.autoexpand Issued when a vdev can be automatically expanded.
io_failure Issued when there is an I/O failure in a vdev in the pool.
probe_failure Issued when a probe fails on a vdev. This would occur if a vdev have
been kicked from the system outside of ZFS (such as the kernel have
removed the device).
log_replay Issued when the intent log cannot be replayed. The can occur in the case
of a missing or damaged log device.
resilver.start Issued when a resilver is started.
resilver.finish Issued when the running resilver have finished.
scrub.start Issued when a scrub is started on a pool.
scrub.finish Issued when a pool has finished scrubbing.
scrub.abort Issued when a scrub is aborted on a pool.
scrub.resume Issued when a scrub is resumed on a pool.
scrub.paused Issued when a scrub is paused on a pool.
bootfs.vdev.attach
PAYLOADS
This is the payload (data, information) that accompanies an event.
For zed(8), these are set to uppercase and prefixed with ZEVENT_.
pool Pool name.
pool_failmode Failmode - wait, continue, or panic. See the failmode property in
zpoolprops(7) for more information.
pool_guid The GUID of the pool.
pool_context The load state for the pool (0=none, 1=open, 2=import, 3=tryimport,
4=recover 5=error).
vdev_guid The GUID of the vdev in question (the vdev failing or operated upon with
zpool clear, etc.).
vdev_type Type of vdev - disk, file, mirror, etc. See the Virtual Devices section
of zpoolconcepts(7) for more information on possible values.
vdev_path Full path of the vdev, including any -partX.
vdev_devid ID of vdev (if any).
vdev_fru Physical FRU location.
vdev_state State of vdev (0=uninitialized, 1=closed, 2=offline, 3=removed, 4=failed
to open, 5=faulted, 6=degraded, 7=healthy).
vdev_ashift The ashift value of the vdev.
vdev_complete_ts The time the last I/O request completed for the specified vdev.
vdev_delta_ts The time since the last I/O request completed for the specified vdev.
vdev_spare_paths List of spares, including full path and any -partX.
vdev_spare_guids GUID(s) of spares.
vdev_read_errors How many read errors that have been detected on the vdev.
vdev_write_errors How many write errors that have been detected on the vdev.
vdev_cksum_errors How many checksum errors that have been detected on the vdev.
parent_guid GUID of the vdev parent.
parent_type Type of parent. See vdev_type.
parent_path Path of the vdev parent (if any).
parent_devid ID of the vdev parent (if any).
zio_objset The object set number for a given I/O request.
zio_object The object number for a given I/O request.
zio_level The indirect level for the block. Level 0 is the lowest level and
includes data blocks. Values > 0 indicate metadata blocks at the
appropriate level.
zio_blkid The block ID for a given I/O request.
zio_err The error number for a failure when handling a given I/O request,
compatible with errno(3) with the value of EBADE used to indicate a ZFS
checksum error.
zio_offset The offset in bytes of where to write the I/O request for the specified
vdev.
zio_size The size in bytes of the I/O request.
zio_flags The current flags describing how the I/O request should be handled. See
the I/O FLAGS section for the full list of I/O flags.
zio_stage The current stage of the I/O in the pipeline. See the I/O STAGES section
for a full list of all the I/O stages.
zio_pipeline The valid pipeline stages for the I/O. See the I/O STAGES section for a
full list of all the I/O stages.
zio_delay The time elapsed (in nanoseconds) waiting for the block layer to complete
the I/O request. Unlike zio_delta, this does not include any vdev
queuing time and is therefore solely a measure of the block layer
performance.
zio_timestamp The time when a given I/O request was submitted.
zio_delta The time required to service a given I/O request.
prev_state The previous state of the vdev.
cksum_expected The expected checksum value for the block.
cksum_actual The actual checksum value for an errant block.
cksum_algorithm Checksum algorithm used. See zfsprops(7) for more information on the
available checksum algorithms.
cksum_byteswap Whether or not the data is byteswapped.
bad_ranges [start, end) pairs of corruption offsets. Offsets are always aligned on
a 64-bit boundary, and can include some gaps of non-corruption. (See
bad_ranges_min_gap)
bad_ranges_min_gap
In order to bound the size of the bad_ranges array, gaps of non-
corruption less than or equal to bad_ranges_min_gap bytes have been
merged with adjacent corruption. Always at least 8 bytes, since
corruption is detected on a 64-bit word basis.
bad_range_sets This array has one element per range in bad_ranges. Each element
contains the count of bits in that range which were clear in the good
data and set in the bad data.
bad_range_clears This array has one element per range in bad_ranges. Each element
contains the count of bits for that range which were set in the good data
and clear in the bad data.
bad_set_bits If this field exists, it is an array of (bad data & ~(good data)); that
is, the bits set in the bad data which are cleared in the good data.
Each element corresponds a byte whose offset is in a range in bad_ranges,
and the array is ordered by offset. Thus, the first element is the first
byte in the first bad_ranges range, and the last element is the last byte
in the last bad_ranges range.
bad_cleared_bits Like bad_set_bits, but contains (good data & ~(bad data)); that is, the
bits set in the good data which are cleared in the bad data.
bad_set_histogram If this field exists, it is an array of counters. Each entry counts bits
set in a particular bit of a big-endian uint64 type. The first entry
counts bits set in the high-order bit of the first byte, the 9th byte,
etc, and the last entry counts bits set of the low-order bit of the 8th
byte, the 16th byte, etc. This information is useful for observing a
stuck bit in a parallel data path, such as IDE or parallel SCSI.
bad_cleared_histogram
If this field exists, it is an array of counters. Each entry counts bit
clears in a particular bit of a big-endian uint64 type. The first entry
counts bits clears of the high-order bit of the first byte, the 9th byte,
etc, and the last entry counts clears of the low-order bit of the 8th
byte, the 16th byte, etc. This information is useful for observing a
stuck bit in a parallel data path, such as IDE or parallel SCSI.
I/O STAGES
The ZFS I/O pipeline is comprised of various stages which are defined below. The individual
stages are used to construct these basic I/O operations: Read, Write, Free, Claim, and
Ioctl. These stages may be set on an event to describe the life cycle of a given I/O
request.
Stage Bit Mask Operations
──────────────────────────────────────────────────────
ZIO_STAGE_OPEN 0x00000001 RWFCI
ZIO_STAGE_READ_BP_INIT 0x00000002 R----
ZIO_STAGE_WRITE_BP_INIT 0x00000004 -W---
ZIO_STAGE_FREE_BP_INIT 0x00000008 --F--
ZIO_STAGE_ISSUE_ASYNC 0x00000010 RWF--
ZIO_STAGE_WRITE_COMPRESS 0x00000020 -W---
ZIO_STAGE_ENCRYPT 0x00000040 -W---
ZIO_STAGE_CHECKSUM_GENERATE 0x00000080 -W---
ZIO_STAGE_NOP_WRITE 0x00000100 -W---
ZIO_STAGE_DDT_READ_START 0x00000200 R----
ZIO_STAGE_DDT_READ_DONE 0x00000400 R----
ZIO_STAGE_DDT_WRITE 0x00000800 -W---
ZIO_STAGE_DDT_FREE 0x00001000 --F--
ZIO_STAGE_GANG_ASSEMBLE 0x00002000 RWFC-
ZIO_STAGE_GANG_ISSUE 0x00004000 RWFC-
ZIO_STAGE_DVA_THROTTLE 0x00008000 -W---
ZIO_STAGE_DVA_ALLOCATE 0x00010000 -W---
ZIO_STAGE_DVA_FREE 0x00020000 --F--
ZIO_STAGE_DVA_CLAIM 0x00040000 ---C-
ZIO_STAGE_READY 0x00080000 RWFCI
ZIO_STAGE_VDEV_IO_START 0x00100000 RW--I
ZIO_STAGE_VDEV_IO_DONE 0x00200000 RW--I
ZIO_STAGE_VDEV_IO_ASSESS 0x00400000 RW--I
ZIO_STAGE_CHECKSUM_VERIFY 0x00800000 R----
ZIO_STAGE_DONE 0x01000000 RWFCI
I/O FLAGS
Every I/O request in the pipeline contains a set of flags which describe its function and
are used to govern its behavior. These flags will be set in an event as a zio_flags payload
entry.
Flag Bit Mask
─────────────────────────────────────
ZIO_FLAG_DONT_AGGREGATE 0x00000001
ZIO_FLAG_IO_REPAIR 0x00000002
ZIO_FLAG_SELF_HEAL 0x00000004
ZIO_FLAG_RESILVER 0x00000008
ZIO_FLAG_SCRUB 0x00000010
ZIO_FLAG_SCAN_THREAD 0x00000020
ZIO_FLAG_PHYSICAL 0x00000040
ZIO_FLAG_CANFAIL 0x00000080
ZIO_FLAG_SPECULATIVE 0x00000100
ZIO_FLAG_CONFIG_WRITER 0x00000200
ZIO_FLAG_DONT_RETRY 0x00000400
ZIO_FLAG_DONT_CACHE 0x00000800
ZIO_FLAG_NODATA 0x00001000
ZIO_FLAG_INDUCE_DAMAGE 0x00002000
ZIO_FLAG_IO_ALLOCATING 0x00004000
ZIO_FLAG_IO_RETRY 0x00008000
ZIO_FLAG_PROBE 0x00010000
ZIO_FLAG_TRYHARD 0x00020000
ZIO_FLAG_OPTIONAL 0x00040000
ZIO_FLAG_DONT_QUEUE 0x00080000
ZIO_FLAG_DONT_PROPAGATE 0x00100000
ZIO_FLAG_IO_BYPASS 0x00200000
ZIO_FLAG_IO_REWRITE 0x00400000
ZIO_FLAG_RAW_COMPRESS 0x00800000
ZIO_FLAG_RAW_ENCRYPT 0x01000000
ZIO_FLAG_GANG_CHILD 0x02000000
ZIO_FLAG_DDT_CHILD 0x04000000
ZIO_FLAG_GODFATHER 0x08000000
ZIO_FLAG_NOPWRITE 0x10000000
ZIO_FLAG_REEXECUTED 0x20000000
ZIO_FLAG_DELEGATED 0x40000000
ZIO_FLAG_FASTWRITE 0x80000000
SEE ALSO
zfs(4), zed(8), zpool-wait(8)