Provided by: zfsutils-linux_0.7.5-1ubuntu16.12_amd64 
NAME
zfs-events - Events created by the ZFS filesystem.
DESCRIPTION
Description of the different events generated by the ZFS stack.
Most of these don't have any description. The events generated by ZFS have never been
publicly documented. What is here is intended as a starting point to provide
documentation for all possible events.
To view all events created since the loading of the ZFS infrastructure (i.e, "the
module"), run
zpool events
to get a short list, and
zpool events -v
to get a full detail of the events and what information is available about it.
This man page lists the different subclasses that are issued in the case of an event. The
full event name would be ereport.fs.zfs.SUBCLASS, but we only list the last part here.
EVENTS (SUBCLASS)
checksum
Issued when a checksum error have 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.
delay
Issued when an I/O was slow to complete as defined by the zio_delay_max module
option.
config.sync
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 readded).
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 have finished scrubbing.
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 pool(8) (failmode property) 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 zpool(8) under Virtual Devices 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 completed for the specified vdev.
vdev_delta_ts
The time since the last I/O 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 checkum 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.
zio_object
The object number for a given I/O.
zio_level
The block level for a given I/O.
zio_blkid
The block ID for a given I/O.
zio_err
The errno for a failure when handling a given I/O.
zio_offset
The offset in bytes of where to write the I/O for the specified vdev.
zio_size
The size in bytes of the I/O.
zio_flags
The current flags describing how the I/O 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 in ticks (HZ) required for the block layer to service the I/O.
Unlike zio_delta this does not include any vdev queuing time and is therefore
solely a measure of the block layer performance. On most modern Linux systems
HZ is defined as 1000 making a tick equivalent to 1 millisecond.
zio_timestamp
The time when a given I/O was submitted.
zio_delta
The time required to service a given I/O.
prev_state
The previous state of the vdev.
cksum_expected
The expected checksum value.
cksum_actual
The actual/current checksum value.
cksum_algorithm
Checksum algorithm used. See zfs(8) for more information on checksum
algorithms available.
cksum_byteswap
Checksum value is byte swapped.
bad_ranges
Checksum bad offset ranges.
bad_ranges_min_gap
Checksum allowed minimum gap.
bad_range_sets
Checksum for each range the number of bits set.
bad_range_clears
Checksum for each range the number of bits cleared.
bad_set_bits
Checksum array of bits set.
bad_cleared_bits
Checksum array of bits cleared.
bad_set_histogram
Checksum histogram of set bits by bit number in a 64-bit word.
bad_cleared_histogram
Checksum histogram of cleared bits by bit number in a 64-bit word.
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.
Stage Bit Mask Operations
──────────────────────────────────────────────────────
ZIO_STAGE_OPEN 0x00000001 RWFCI
ZIO_STAGE_READ_BP_INIT 0x00000002 R----
ZIO_STAGE_FREE_BP_INIT 0x00000004 --F--
ZIO_STAGE_ISSUE_ASYNC 0x00000008 RWF--
ZIO_STAGE_WRITE_BP_INIT 0x00000010 -W---
ZIO_STAGE_CHECKSUM_GENERATE 0x00000020 -W---
ZIO_STAGE_NOP_WRITE 0x00000040 -W---
ZIO_STAGE_DDT_READ_START 0x00000080 R----
ZIO_STAGE_DDT_READ_DONE 0x00000100 R----
ZIO_STAGE_DDT_WRITE 0x00000200 -W---
ZIO_STAGE_DDT_FREE 0x00000400 --F--
ZIO_STAGE_GANG_ASSEMBLE 0x00000800 RWFC-
ZIO_STAGE_GANG_ISSUE 0x00001000 RWFC-
ZIO_STAGE_DVA_ALLOCATE 0x00002000 -W---
ZIO_STAGE_DVA_FREE 0x00004000 --F--
ZIO_STAGE_DVA_CLAIM 0x00008000 ---C-
ZIO_STAGE_READY 0x00010000 RWFCI
ZIO_STAGE_VDEV_IO_START 0x00020000 RW--I
ZIO_STAGE_VDEV_IO_DONE 0x00040000 RW--I
ZIO_STAGE_VDEV_IO_ASSESS 0x00080000 RW--I
ZIO_STAGE_CHECKSUM_VERIFY0 0x00100000 R----
ZIO_STAGE_DONE 0x00200000 RWFCI
I/O FLAGS
Every I/O 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 an 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_RETRY 0x00004000
ZIO_FLAG_PROBE 0x00008000
ZIO_FLAG_TRYHARD 0x00010000
ZIO_FLAG_OPTIONAL 0x00020000
ZIO_FLAG_DONT_QUEUE 0x00040000
ZIO_FLAG_DONT_PROPAGATE 0x00080000
ZIO_FLAG_IO_BYPASS 0x00100000
ZIO_FLAG_IO_REWRITE 0x00200000
ZIO_FLAG_RAW 0x00400000
ZIO_FLAG_GANG_CHILD 0x00800000
ZIO_FLAG_DDT_CHILD 0x01000000
ZIO_FLAG_GODFATHER 0x02000000
ZIO_FLAG_NOPWRITE 0x04000000
ZIO_FLAG_REEXECUTED 0x08000000
ZIO_FLAG_DELEGATED 0x10000000
ZIO_FLAG_FASTWRITE 0x20000000
Jun 6, 2015 ZFS-EVENTS(5)