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If applicable, add the following below this .\" CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your .\" own identifying information: .\" Portions Copyright [yyyy] [name of copyright owner] .TH ZFS-EVENTS 5 "Aug 24, 2020" OpenZFS .SH NAME zfs\-events \- Events created by the ZFS filesystem. .SH DESCRIPTION .sp .LP Description of the different events generated by the ZFS stack. .sp 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. .sp To view all events created since the loading of the ZFS infrastructure (i.e, "the module"), run .P .nf \fBzpool events\fR .fi .P to get a short list, and .P .nf \fBzpool events -v\fR .fi .P to get a full detail of the events and what information is available about it. .sp This man page lists the different subclasses that are issued in the case of an event. The full event name would be \fIereport.fs.zfs.SUBCLASS\fR, but we only list the last part here. .SS "EVENTS (SUBCLASS)" .sp .LP .sp .ne 2 .na \fBchecksum\fR .ad .RS 12n Issued when a checksum error has been detected. .RE .sp .ne 2 .na \fBio\fR .ad .RS 12n Issued when there is an I/O error in a vdev in the pool. .RE .sp .ne 2 .na \fBdata\fR .ad .RS 12n Issued when there have been data errors in the pool. .RE .sp .ne 2 .na \fBdeadman\fR .ad .RS 12n 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 \fBzfs_deadman_failmode\fR module option description for additional information regarding "hung" I/O detection and configuration. .RE .sp .ne 2 .na \fBdelay\fR .ad .RS 12n Issued when a completed I/O exceeds the maximum allowed time specified by the \fBzio_slow_io_ms\fR module option. This can be an indicator of problems with the underlying storage device. The number of delay events is ratelimited by the \fBzfs_slow_io_events_per_second\fR module parameter. .RE .sp .ne 2 .na \fBconfig.sync\fR .ad .RS 12n Issued every time a vdev change have been done to the pool. .RE .sp .ne 2 .na \fBzpool\fR .ad .RS 12n Issued when a pool cannot be imported. .RE .sp .ne 2 .na \fBzpool.destroy\fR .ad .RS 12n Issued when a pool is destroyed. .RE .sp .ne 2 .na \fBzpool.export\fR .ad .RS 12n Issued when a pool is exported. .RE .sp .ne 2 .na \fBzpool.import\fR .ad .RS 12n Issued when a pool is imported. .RE .sp .ne 2 .na \fBzpool.reguid\fR .ad .RS 12n Issued when a REGUID (new unique identifier for the pool have been regenerated) have been detected. .RE .sp .ne 2 .na \fBvdev.unknown\fR .ad .RS 12n 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. .RE .sp .ne 2 .na \fBvdev.open_failed\fR .ad .RS 12n Issued when a vdev could not be opened (because it didn't exist for example). .RE .sp .ne 2 .na \fBvdev.corrupt_data\fR .ad .RS 12n Issued when corrupt data have been detected on a vdev. .RE .sp .ne 2 .na \fBvdev.no_replicas\fR .ad .RS 12n Issued when there are no more replicas to sustain the pool. This would lead to the pool being \fIDEGRADED\fR. .RE .sp .ne 2 .na \fBvdev.bad_guid_sum\fR .ad .RS 12n Issued when a missing device in the pool have been detected. .RE .sp .ne 2 .na \fBvdev.too_small\fR .ad .RS 12n 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 \fBprobe_failure\fR event. .RE .sp .ne 2 .na \fBvdev.bad_label\fR .ad .RS 12n Issued when the label is OK but invalid. .RE .sp .ne 2 .na \fBvdev.bad_ashift\fR .ad .RS 12n Issued when the ashift alignment requirement has increased. .RE .sp .ne 2 .na \fBvdev.remove\fR .ad .RS 12n 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). .RE .sp .ne 2 .na \fBvdev.clear\fR .ad .RS 12n Issued when clearing device errors in a pool. Such as running \fBzpool clear\fR on a device in the pool. .RE .sp .ne 2 .na \fBvdev.check\fR .ad .RS 12n Issued when a check to see if a given vdev could be opened is started. .RE .sp .ne 2 .na \fBvdev.spare\fR .ad .RS 12n Issued when a spare have kicked in to replace a failed device. .RE .sp .ne 2 .na \fBvdev.autoexpand\fR .ad .RS 12n Issued when a vdev can be automatically expanded. .RE .sp .ne 2 .na \fBio_failure\fR .ad .RS 12n Issued when there is an I/O failure in a vdev in the pool. .RE .sp .ne 2 .na \fBprobe_failure\fR .ad .RS 12n 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). .RE .sp .ne 2 .na \fBlog_replay\fR .ad .RS 12n Issued when the intent log cannot be replayed. The can occur in the case of a missing or damaged log device. .RE .sp .ne 2 .na \fBresilver.start\fR .ad .RS 12n Issued when a resilver is started. .RE .sp .ne 2 .na \fBresilver.finish\fR .ad .RS 12n Issued when the running resilver have finished. .RE .sp .ne 2 .na \fBscrub.start\fR .ad .RS 12n Issued when a scrub is started on a pool. .RE .sp .ne 2 .na \fBscrub.finish\fR .ad .RS 12n Issued when a pool has finished scrubbing. .RE .sp .ne 2 .na \fBscrub.abort\fR .ad .RS 12n Issued when a scrub is aborted on a pool. .RE .sp .ne 2 .na \fBscrub.resume\fR .ad .RS 12n Issued when a scrub is resumed on a pool. .RE .sp .ne 2 .na \fBscrub.paused\fR .ad .RS 12n Issued when a scrub is paused on a pool. .RE .sp .ne 2 .na \fBbootfs.vdev.attach\fR .ad .RS 12n .RE .SS "PAYLOADS" .sp .LP This is the payload (data, information) that accompanies an event. .sp For .BR zed (8), these are set to uppercase and prefixed with \fBZEVENT_\fR. .sp .ne 2 .na \fBpool\fR .ad .RS 12n Pool name. .RE .sp .ne 2 .na \fBpool_failmode\fR .ad .RS 12n Failmode - \fBwait\fR, \fBcontinue\fR or \fBpanic\fR. See .BR zpool (8) (\fIfailmode\fR property) for more information. .RE .sp .ne 2 .na \fBpool_guid\fR .ad .RS 12n The GUID of the pool. .RE .sp .ne 2 .na \fBpool_context\fR .ad .RS 12n The load state for the pool (0=none, 1=open, 2=import, 3=tryimport, 4=recover 5=error). .RE .sp .ne 2 .na \fBvdev_guid\fR .ad .RS 12n The GUID of the vdev in question (the vdev failing or operated upon with \fBzpool clear\fR etc). .RE .sp .ne 2 .na \fBvdev_type\fR .ad .RS 12n Type of vdev - \fBdisk\fR, \fBfile\fR, \fBmirror\fR etc. See .BR zpool (8) under \fBVirtual Devices\fR for more information on possible values. .RE .sp .ne 2 .na \fBvdev_path\fR .ad .RS 12n Full path of the vdev, including any \fI-partX\fR. .RE .sp .ne 2 .na \fBvdev_devid\fR .ad .RS 12n ID of vdev (if any). .RE .sp .ne 2 .na \fBvdev_fru\fR .ad .RS 12n Physical FRU location. .RE .sp .ne 2 .na \fBvdev_state\fR .ad .RS 12n State of vdev (0=uninitialized, 1=closed, 2=offline, 3=removed, 4=failed to open, 5=faulted, 6=degraded, 7=healthy). .RE .sp .ne 2 .na \fBvdev_ashift\fR .ad .RS 12n The ashift value of the vdev. .RE .sp .ne 2 .na \fBvdev_complete_ts\fR .ad .RS 12n The time the last I/O completed for the specified vdev. .RE .sp .ne 2 .na \fBvdev_delta_ts\fR .ad .RS 12n The time since the last I/O completed for the specified vdev. .RE .sp .ne 2 .na \fBvdev_spare_paths\fR .ad .RS 12n List of spares, including full path and any \fI-partX\fR. .RE .sp .ne 2 .na \fBvdev_spare_guids\fR .ad .RS 12n GUID(s) of spares. .RE .sp .ne 2 .na \fBvdev_read_errors\fR .ad .RS 12n How many read errors that have been detected on the vdev. .RE .sp .ne 2 .na \fBvdev_write_errors\fR .ad .RS 12n How many write errors that have been detected on the vdev. .RE .sp .ne 2 .na \fBvdev_cksum_errors\fR .ad .RS 12n How many checksum errors that have been detected on the vdev. .RE .sp .ne 2 .na \fBparent_guid\fR .ad .RS 12n GUID of the vdev parent. .RE .sp .ne 2 .na \fBparent_type\fR .ad .RS 12n Type of parent. See \fBvdev_type\fR. .RE .sp .ne 2 .na \fBparent_path\fR .ad .RS 12n Path of the vdev parent (if any). .RE .sp .ne 2 .na \fBparent_devid\fR .ad .RS 12n ID of the vdev parent (if any). .RE .sp .ne 2 .na \fBzio_objset\fR .ad .RS 12n The object set number for a given I/O. .RE .sp .ne 2 .na \fBzio_object\fR .ad .RS 12n The object number for a given I/O. .RE .sp .ne 2 .na \fBzio_level\fR .ad .RS 12n 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. .RE .sp .ne 2 .na \fBzio_blkid\fR .ad .RS 12n The block ID for a given I/O. .RE .sp .ne 2 .na \fBzio_err\fR .ad .RS 12n The errno for a failure when handling a given I/O. The errno is compatible with \fBerrno\fR(3) with the value for EBADE (0x34) used to indicate ZFS checksum error. .RE .sp .ne 2 .na \fBzio_offset\fR .ad .RS 12n The offset in bytes of where to write the I/O for the specified vdev. .RE .sp .ne 2 .na \fBzio_size\fR .ad .RS 12n The size in bytes of the I/O. .RE .sp .ne 2 .na \fBzio_flags\fR .ad .RS 12n The current flags describing how the I/O should be handled. See the \fBI/O FLAGS\fR section for the full list of I/O flags. .RE .sp .ne 2 .na \fBzio_stage\fR .ad .RS 12n The current stage of the I/O in the pipeline. See the \fBI/O STAGES\fR section for a full list of all the I/O stages. .RE .sp .ne 2 .na \fBzio_pipeline\fR .ad .RS 12n The valid pipeline stages for the I/O. See the \fBI/O STAGES\fR section for a full list of all the I/O stages. .RE .sp .ne 2 .na \fBzio_delay\fR .ad .RS 12n The time elapsed (in nanoseconds) waiting for the block layer to complete the I/O. Unlike \fBzio_delta\fR this does not include any vdev queuing time and is therefore solely a measure of the block layer performance. .RE .sp .ne 2 .na \fBzio_timestamp\fR .ad .RS 12n The time when a given I/O was submitted. .RE .sp .ne 2 .na \fBzio_delta\fR .ad .RS 12n The time required to service a given I/O. .RE .sp .ne 2 .na \fBprev_state\fR .ad .RS 12n The previous state of the vdev. .RE .sp .ne 2 .na \fBcksum_expected\fR .ad .RS 12n The expected checksum value for the block. .RE .sp .ne 2 .na \fBcksum_actual\fR .ad .RS 12n The actual checksum value for an errant block. .RE .sp .ne 2 .na \fBcksum_algorithm\fR .ad .RS 12n Checksum algorithm used. See \fBzfs\fR(8) for more information on checksum algorithms available. .RE .sp .ne 2 .na \fBcksum_byteswap\fR .ad .RS 12n Whether or not the data is byteswapped. .RE .sp .ne 2 .na \fBbad_ranges\fR .ad .RS 12n [start, end) pairs of corruption offsets. Offsets are always aligned on a 64-bit boundary, and can include some gaps of non-corruption. (See \fBbad_ranges_min_gap\fR) .RE .sp .ne 2 .na \fBbad_ranges_min_gap\fR .ad .RS 12n In order to bound the size of the \fBbad_ranges\fR array, gaps of non-corruption less than or equal to \fBbad_ranges_min_gap\fR bytes have been merged with adjacent corruption. Always at least 8 bytes, since corruption is detected on a 64-bit word basis. .RE .sp .ne 2 .na \fBbad_range_sets\fR .ad .RS 12n This array has one element per range in \fBbad_ranges\fR. Each element contains the count of bits in that range which were clear in the good data and set in the bad data. .RE .sp .ne 2 .na \fBbad_range_clears\fR .ad .RS 12n This array has one element per range in \fBbad_ranges\fR. Each element contains the count of bits for that range which were set in the good data and clear in the bad data. .RE .sp .ne 2 .na \fBbad_set_bits\fR .ad .RS 12n 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 \fBbad_ranges\fR, and the array is ordered by offset. Thus, the first element is the first byte in the first \fBbad_ranges\fR range, and the last element is the last byte in the last \fBbad_ranges\fR range. .RE .sp .ne 2 .na \fBbad_cleared_bits\fR .ad .RS 12n Like \fBbad_set_bits\fR, but contains: (good data & ~(bad data)); that is, the bits set in the good data which are cleared in the bad data. .RE .sp .ne 2 .na \fBbad_set_histogram\fR .ad .RS 12n 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. .RE .sp .ne 2 .na \fBbad_cleared_histogram\fR .ad .RS 12n 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. .RE .SS "I/O STAGES" .sp .LP 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. .TS tab(:); l l l . 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 .TE .SS "I/O FLAGS" .sp .LP 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 \fBzio_flags\fR payload entry. .TS tab(:); l l . 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 .TE