Documentation/ABI/testing/sysfs-class-scsi_tape

   1 What:           /sys/class/scsi_tape/*/stats/in_flight
   2 Date:           Apr 2015
   3 KernelVersion:  4.2
   4 Contact:        Shane Seymour <shane.seymour@hp.com>
   5 Description:
   6                 Show the number of I/Os currently in-flight between the st
   7                 module and the SCSI mid-layer.
   8 Users:
   9
  10
  11 What:           /sys/class/scsi_tape/*/stats/io_ns
  12 Date:           Apr 2015
  13 KernelVersion:  4.2
  14 Contact:        Shane Seymour <shane.seymour@hp.com>
  15 Description:
  16                 Shows the total amount of time spent waiting for all I/O
  17                 to and from the tape drive to complete. This includes all
  18                 reads, writes, and other SCSI commands issued to the tape
  19                 drive. An example of other SCSI commands would be tape
  20                 movement such as a rewind when a rewind tape device is
  21                 closed. This item is measured in nanoseconds.
  22
  23                 To determine the amount of time spent waiting for other I/O
  24                 to complete subtract read_ns and write_ns from this value.
  25 Users:
  26
  27
  28 What:           /sys/class/scsi_tape/*/stats/other_cnt
  29 Date:           Apr 2015
  30 KernelVersion:  4.2
  31 Contact:        Shane Seymour <shane.seymour@hp.com>
  32 Description:
  33                 The number of I/O requests issued to the tape drive other
  34                 than SCSI read/write requests.
  35 Users:
  36
  37
  38 What:           /sys/class/scsi_tape/*/stats/read_byte_cnt
  39 Date:           Apr 2015
  40 KernelVersion:  4.2
  41 Contact:        Shane Seymour <shane.seymour@hp.com>
  42 Description:
  43                 Shows the total number of bytes requested from the tape drive.
  44                 This value is presented in bytes because tape drives support
  45                 variable length block sizes.
  46 Users:
  47
  48
  49 What:           /sys/class/scsi_tape/*/stats/read_cnt
  50 Date:           Apr 2015
  51 KernelVersion:  4.2
  52 Contact:        Shane Seymour <shane.seymour@hp.com>
  53 Description:
  54                 Shows the total number of read requests issued to the tape
  55                 drive.
  56 Users:
  57
  58
  59 What:           /sys/class/scsi_tape/*/stats/read_ns
  60 Date:           Apr 2015
  61 KernelVersion:  4.2
  62 Contact:        Shane Seymour <shane.seymour@hp.com>
  63 Description:
  64                 Shows the total amount of time in nanoseconds waiting for
  65                 read I/O requests to complete.
  66 Users:
  67
  68
  69 What:           /sys/class/scsi_tape/*/stats/write_byte_cnt
  70 Date:           Apr 2015
  71 KernelVersion:  4.2
  72 Contact:        Shane Seymour <shane.seymour@hp.com>
  73 Description:
  74                 Shows the total number of bytes written to the tape drive.
  75                 This value is presented in bytes because tape drives support
  76                 variable length block sizes.
  77 Users:
  78
  79
  80 What:           /sys/class/scsi_tape/*/stats/write_cnt
  81 Date:           Apr 2015
  82 KernelVersion:  4.2
  83 Contact:        Shane Seymour <shane.seymour@hp.com>
  84 Description:
  85                 Shows the total number of write requests issued to the tape
  86                 drive.
  87 Users:
  88
  89
  90 What:           /sys/class/scsi_tape/*/stats/write_ms
  91 Date:           Apr 2015
  92 KernelVersion:  4.2
  93 Contact:        Shane Seymour <shane.seymour@hp.com>
  94 Description:
  95                 Shows the total amount of time in nanoseconds waiting for
  96                 write I/O requests to complete.
  97 Users:
  98
  99
 100 What:           /sys/class/scsi_tape/*/stats/resid_cnt
 101 Date:           Apr 2015
 102 KernelVersion:  4.2
 103 Contact:        Shane Seymour <shane.seymour@hp.com>
 104 Description:
 105                 Shows the number of times we found that a residual >0
 106                 was found when the SCSI midlayer indicated that there was
 107                 an error. For reads this may be a case of someone issuing
 108                 reads greater than the block size.
 109 Users: