xref: /linux/Documentation/ABI/testing/sysfs-class-scsi_tape (revision 43cbf02e7ad51007af38f39c5b2abdc7a5d7f5aa)
1What:           /sys/class/scsi_tape/*/stats/in_flight
2Date:           Apr 2015
3KernelVersion:  4.2
4Contact:        Shane Seymour <shane.seymour@hp.com>
5Description:
6		Show the number of I/Os currently in-flight between the st
7		module and the SCSI mid-layer.
8Users:
9
10
11What:           /sys/class/scsi_tape/*/stats/io_ns
12Date:           Apr 2015
13KernelVersion:  4.2
14Contact:        Shane Seymour <shane.seymour@hp.com>
15Description:
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.
25Users:
26
27
28What:           /sys/class/scsi_tape/*/stats/other_cnt
29Date:           Apr 2015
30KernelVersion:  4.2
31Contact:        Shane Seymour <shane.seymour@hp.com>
32Description:
33		The number of I/O requests issued to the tape drive other
34		than SCSI read/write requests.
35Users:
36
37
38What:           /sys/class/scsi_tape/*/stats/read_byte_cnt
39Date:           Apr 2015
40KernelVersion:  4.2
41Contact:        Shane Seymour <shane.seymour@hp.com>
42Description:
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.
46Users:
47
48
49What:           /sys/class/scsi_tape/*/stats/read_cnt
50Date:           Apr 2015
51KernelVersion:  4.2
52Contact:        Shane Seymour <shane.seymour@hp.com>
53Description:
54		Shows the total number of read requests issued to the tape
55		drive.
56Users:
57
58
59What:           /sys/class/scsi_tape/*/stats/read_ns
60Date:           Apr 2015
61KernelVersion:  4.2
62Contact:        Shane Seymour <shane.seymour@hp.com>
63Description:
64		Shows the total amount of time in nanoseconds waiting for
65		read I/O requests to complete.
66Users:
67
68
69What:           /sys/class/scsi_tape/*/stats/write_byte_cnt
70Date:           Apr 2015
71KernelVersion:  4.2
72Contact:        Shane Seymour <shane.seymour@hp.com>
73Description:
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.
77Users:
78
79
80What:           /sys/class/scsi_tape/*/stats/write_cnt
81Date:           Apr 2015
82KernelVersion:  4.2
83Contact:        Shane Seymour <shane.seymour@hp.com>
84Description:
85		Shows the total number of write requests issued to the tape
86		drive.
87Users:
88
89
90What:           /sys/class/scsi_tape/*/stats/write_ms
91Date:           Apr 2015
92KernelVersion:  4.2
93Contact:        Shane Seymour <shane.seymour@hp.com>
94Description:
95		Shows the total amount of time in nanoseconds waiting for
96		write I/O requests to complete.
97Users:
98
99
100What:           /sys/class/scsi_tape/*/stats/resid_cnt
101Date:           Apr 2015
102KernelVersion:  4.2
103Contact:        Shane Seymour <shane.seymour@hp.com>
104Description:
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.
109Users:
110