Provided by: zfsutils-linux_0.8.3-1ubuntu12.18_amd64 bug

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 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 is determined to be "hung", this can be caused by lost  completion  events
                   due to flaky hardware or drivers.  See the zfs_deadman_failmode module option description for
                   additional information regarding "hung" I/O detection and configuration.

       delay
                   Issued when a completed I/O exceeds the maximum allowed time specified by the  zio_slow_io_ms
                   module option.  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.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 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 zpool(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 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.

       zio_object
                   The object number for a given I/O.

       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.

       zio_err
                   The errno for a failure when handling a given I/O. The errno is compatible with errno(3) with
                   the value for EBADE (0x34) used to indicate ZFS checksum error.

       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  elapsed  (in nanoseconds) waiting for the block layer to complete 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.

       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 for the block.

       cksum_actual
                   The actual checksum value for an errant block.

       cksum_algorithm
                   Checksum algorithm used. See zfs(8) for more information on checksum algorithms available.

       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.

       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 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_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

                                                  Oct 24, 2018                                     ZFS-EVENTS(5)