^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) What: /sys/block/<disk>/stat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) Date: February 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Contact: Jerome Marchand <jmarchan@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) The /sys/block/<disk>/stat files displays the I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) statistics of disk <disk>. They contain 11 fields:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) == ==============================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) 1 reads completed successfully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 2 reads merged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 3 sectors read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 4 time spent reading (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 5 writes completed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 6 writes merged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 7 sectors written
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 8 time spent writing (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 9 I/Os currently in progress
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 10 time spent doing I/Os (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 11 weighted time spent doing I/Os (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 12 discards completed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 13 discards merged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 14 sectors discarded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 15 time spent discarding (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 16 flush requests completed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 17 time spent flushing (ms)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) == ==============================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) For more details refer Documentation/admin-guide/iostats.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) What: /sys/block/<disk>/<part>/stat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) Date: February 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Contact: Jerome Marchand <jmarchan@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) The /sys/block/<disk>/<part>/stat files display the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) I/O statistics of partition <part>. The format is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) same as the above-written /sys/block/<disk>/stat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) format.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) What: /sys/block/<disk>/integrity/format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) Date: June 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) Metadata format for integrity capable block device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) E.g. T10-DIF-TYPE1-CRC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) What: /sys/block/<disk>/integrity/read_verify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) Date: June 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) Indicates whether the block layer should verify the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) integrity of read requests serviced by devices that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) support sending integrity metadata.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) What: /sys/block/<disk>/integrity/tag_size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) Date: June 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) Number of bytes of integrity tag space available per
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 512 bytes of data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) What: /sys/block/<disk>/integrity/device_is_integrity_capable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) Date: July 2014
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) Indicates whether a storage device is capable of storing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) integrity metadata. Set if the device is T10 PI-capable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) What: /sys/block/<disk>/integrity/protection_interval_bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) Date: July 2015
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) Describes the number of data bytes which are protected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) by one integrity tuple. Typically the device's logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) block size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) What: /sys/block/<disk>/integrity/write_generate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) Date: June 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) Indicates whether the block layer should automatically
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) generate checksums for write requests bound for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) devices that support receiving integrity metadata.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) What: /sys/block/<disk>/alignment_offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) Date: April 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) Storage devices may report a physical block size that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) bigger than the logical block size (for instance a drive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) with 4KB physical sectors exposing 512-byte logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) blocks to the operating system). This parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) indicates how many bytes the beginning of the device is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) offset from the disk's natural alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) What: /sys/block/<disk>/<partition>/alignment_offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) Date: April 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) Storage devices may report a physical block size that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) bigger than the logical block size (for instance a drive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) with 4KB physical sectors exposing 512-byte logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) blocks to the operating system). This parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) indicates how many bytes the beginning of the partition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) is offset from the disk's natural alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) What: /sys/block/<disk>/queue/logical_block_size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) Date: May 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) This is the smallest unit the storage device can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) address. It is typically 512 bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) What: /sys/block/<disk>/queue/physical_block_size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) Date: May 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) This is the smallest unit a physical storage device can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) write atomically. It is usually the same as the logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) block size but may be bigger. One example is SATA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) drives with 4KB sectors that expose a 512-byte logical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) block size to the operating system. For stacked block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) devices the physical_block_size variable contains the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) maximum physical_block_size of the component devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) What: /sys/block/<disk>/queue/minimum_io_size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) Date: April 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) Storage devices may report a granularity or preferred
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) minimum I/O size which is the smallest request the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) device can perform without incurring a performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) penalty. For disk drives this is often the physical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) block size. For RAID arrays it is often the stripe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) chunk size. A properly aligned multiple of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) minimum_io_size is the preferred request size for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) workloads where a high number of I/O operations is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) desired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) What: /sys/block/<disk>/queue/optimal_io_size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) Date: April 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) Storage devices may report an optimal I/O size, which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) the device's preferred unit for sustained I/O. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) rarely reported for disk drives. For RAID arrays it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) usually the stripe width or the internal track size. A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) properly aligned multiple of optimal_io_size is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) preferred request size for workloads where sustained
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) throughput is desired. If no optimal I/O size is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) reported this file contains 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) What: /sys/block/<disk>/queue/nomerges
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) Date: January 2010
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) Contact:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) Standard I/O elevator operations include attempts to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) merge contiguous I/Os. For known random I/O loads these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) attempts will always fail and result in extra cycles
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) being spent in the kernel. This allows one to turn off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) this behavior on one of two ways: When set to 1, complex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) merge checks are disabled, but the simple one-shot merges
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) with the previous I/O request are enabled. When set to 2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) all merge tries are disabled. The default value is 0 -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) which enables all types of merge tries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) What: /sys/block/<disk>/discard_alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) Date: May 2011
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) Devices that support discard functionality may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) internally allocate space in units that are bigger than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) the exported logical block size. The discard_alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) parameter indicates how many bytes the beginning of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) device is offset from the internal allocation unit's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) natural alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) What: /sys/block/<disk>/<partition>/discard_alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) Date: May 2011
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) Devices that support discard functionality may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) internally allocate space in units that are bigger than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) the exported logical block size. The discard_alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) parameter indicates how many bytes the beginning of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) partition is offset from the internal allocation unit's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) natural alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) What: /sys/block/<disk>/queue/discard_granularity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) Date: May 2011
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) Devices that support discard functionality may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) internally allocate space using units that are bigger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) than the logical block size. The discard_granularity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) parameter indicates the size of the internal allocation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) unit in bytes if reported by the device. Otherwise the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) discard_granularity will be set to match the device's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) physical block size. A discard_granularity of 0 means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) that the device does not support discard functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) What: /sys/block/<disk>/queue/discard_max_bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) Date: May 2011
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) Devices that support discard functionality may have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) internal limits on the number of bytes that can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) trimmed or unmapped in a single operation. Some storage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) protocols also have inherent limits on the number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) blocks that can be described in a single command. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) discard_max_bytes parameter is set by the device driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) to the maximum number of bytes that can be discarded in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) a single operation. Discard requests issued to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) device must not exceed this limit. A discard_max_bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) value of 0 means that the device does not support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) discard functionality.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) What: /sys/block/<disk>/queue/discard_zeroes_data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) Date: May 2011
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) Will always return 0. Don't rely on any specific behavior
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) for discards, and don't read this file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) What: /sys/block/<disk>/queue/write_same_max_bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) Date: January 2012
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) Contact: Martin K. Petersen <martin.petersen@oracle.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) Some devices support a write same operation in which a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) single data block can be written to a range of several
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) contiguous blocks on storage. This can be used to wipe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) areas on disk or to initialize drives in a RAID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) configuration. write_same_max_bytes indicates how many
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) bytes can be written in a single write same command. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) write_same_max_bytes is 0, write same is not supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) by the device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) What: /sys/block/<disk>/queue/write_zeroes_max_bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) Date: November 2016
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) Contact: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) Devices that support write zeroes operation in which a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) single request can be issued to zero out the range of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) contiguous blocks on storage without having any payload
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) in the request. This can be used to optimize writing zeroes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) to the devices. write_zeroes_max_bytes indicates how many
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) bytes can be written in a single write zeroes command. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) write_zeroes_max_bytes is 0, write zeroes is not supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) by the device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) What: /sys/block/<disk>/queue/zoned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) Date: September 2016
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) Contact: Damien Le Moal <damien.lemoal@wdc.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) zoned indicates if the device is a zoned block device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) and the zone model of the device if it is indeed zoned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) The possible values indicated by zoned are "none" for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) regular block devices and "host-aware" or "host-managed"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) for zoned block devices. The characteristics of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) host-aware and host-managed zoned block devices are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) described in the ZBC (Zoned Block Commands) and ZAC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) (Zoned Device ATA Command Set) standards. These standards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) also define the "drive-managed" zone model. However,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) since drive-managed zoned block devices do not support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) zone commands, they will be treated as regular block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) devices and zoned will report "none".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) What: /sys/block/<disk>/queue/nr_zones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) Date: November 2018
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) Contact: Damien Le Moal <damien.lemoal@wdc.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) nr_zones indicates the total number of zones of a zoned block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) device ("host-aware" or "host-managed" zone model). For regular
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) block devices, the value is always 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) What: /sys/block/<disk>/queue/max_active_zones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) Date: July 2020
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) Contact: Niklas Cassel <niklas.cassel@wdc.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) For zoned block devices (zoned attribute indicating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) "host-managed" or "host-aware"), the sum of zones belonging to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) any of the zone states: EXPLICIT OPEN, IMPLICIT OPEN or CLOSED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) is limited by this value. If this value is 0, there is no limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) What: /sys/block/<disk>/queue/max_open_zones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) Date: July 2020
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) Contact: Niklas Cassel <niklas.cassel@wdc.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) For zoned block devices (zoned attribute indicating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) "host-managed" or "host-aware"), the sum of zones belonging to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) any of the zone states: EXPLICIT OPEN or IMPLICIT OPEN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) is limited by this value. If this value is 0, there is no limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) What: /sys/block/<disk>/queue/chunk_sectors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) Date: September 2016
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) Contact: Hannes Reinecke <hare@suse.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) chunk_sectors has different meaning depending on the type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) of the disk. For a RAID device (dm-raid), chunk_sectors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) indicates the size in 512B sectors of the RAID volume
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) stripe segment. For a zoned block device, either
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) host-aware or host-managed, chunk_sectors indicates the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) size in 512B sectors of the zones of the device, with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) the eventual exception of the last zone of the device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) which may be smaller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) What: /sys/block/<disk>/queue/io_timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) Date: November 2018
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) Contact: Weiping Zhang <zhangweiping@didiglobal.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) io_timeout is the request timeout in milliseconds. If a request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) does not complete in this time then the block driver timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) handler is invoked. That timeout handler can decide to retry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) the request, to fail it or to start a device recovery strategy.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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