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)