xref: /OK3568_Linux_fs/kernel/Documentation/ABI/testing/sysfs-class-scsi_tape (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/in_flight
2*4882a593SmuzhiyunDate:           Apr 2015
3*4882a593SmuzhiyunKernelVersion:  4.2
4*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
5*4882a593SmuzhiyunDescription:
6*4882a593Smuzhiyun		Show the number of I/Os currently in-flight between the st
7*4882a593Smuzhiyun		module and the SCSI mid-layer.
8*4882a593SmuzhiyunUsers:
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11*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/io_ns
12*4882a593SmuzhiyunDate:           Apr 2015
13*4882a593SmuzhiyunKernelVersion:  4.2
14*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
15*4882a593SmuzhiyunDescription:
16*4882a593Smuzhiyun		Shows the total amount of time spent waiting for all I/O
17*4882a593Smuzhiyun                to and from the tape drive to complete. This includes all
18*4882a593Smuzhiyun                reads, writes, and other SCSI commands issued to the tape
19*4882a593Smuzhiyun                drive. An example of other SCSI commands would be tape
20*4882a593Smuzhiyun                movement such as a rewind when a rewind tape device is
21*4882a593Smuzhiyun                closed. This item is measured in nanoseconds.
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun                To determine the amount of time spent waiting for other I/O
24*4882a593Smuzhiyun                to complete subtract read_ns and write_ns from this value.
25*4882a593SmuzhiyunUsers:
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27*4882a593Smuzhiyun
28*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/other_cnt
29*4882a593SmuzhiyunDate:           Apr 2015
30*4882a593SmuzhiyunKernelVersion:  4.2
31*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
32*4882a593SmuzhiyunDescription:
33*4882a593Smuzhiyun		The number of I/O requests issued to the tape drive other
34*4882a593Smuzhiyun		than SCSI read/write requests.
35*4882a593SmuzhiyunUsers:
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37*4882a593Smuzhiyun
38*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/read_byte_cnt
39*4882a593SmuzhiyunDate:           Apr 2015
40*4882a593SmuzhiyunKernelVersion:  4.2
41*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
42*4882a593SmuzhiyunDescription:
43*4882a593Smuzhiyun		Shows the total number of bytes requested from the tape drive.
44*4882a593Smuzhiyun		This value is presented in bytes because tape drives support
45*4882a593Smuzhiyun		variable length block sizes.
46*4882a593SmuzhiyunUsers:
47*4882a593Smuzhiyun
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49*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/read_cnt
50*4882a593SmuzhiyunDate:           Apr 2015
51*4882a593SmuzhiyunKernelVersion:  4.2
52*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
53*4882a593SmuzhiyunDescription:
54*4882a593Smuzhiyun		Shows the total number of read requests issued to the tape
55*4882a593Smuzhiyun		drive.
56*4882a593SmuzhiyunUsers:
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58*4882a593Smuzhiyun
59*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/read_ns
60*4882a593SmuzhiyunDate:           Apr 2015
61*4882a593SmuzhiyunKernelVersion:  4.2
62*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
63*4882a593SmuzhiyunDescription:
64*4882a593Smuzhiyun		Shows the total amount of time in nanoseconds waiting for
65*4882a593Smuzhiyun		read I/O requests to complete.
66*4882a593SmuzhiyunUsers:
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69*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/write_byte_cnt
70*4882a593SmuzhiyunDate:           Apr 2015
71*4882a593SmuzhiyunKernelVersion:  4.2
72*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
73*4882a593SmuzhiyunDescription:
74*4882a593Smuzhiyun		Shows the total number of bytes written to the tape drive.
75*4882a593Smuzhiyun		This value is presented in bytes because tape drives support
76*4882a593Smuzhiyun		variable length block sizes.
77*4882a593SmuzhiyunUsers:
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79*4882a593Smuzhiyun
80*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/write_cnt
81*4882a593SmuzhiyunDate:           Apr 2015
82*4882a593SmuzhiyunKernelVersion:  4.2
83*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
84*4882a593SmuzhiyunDescription:
85*4882a593Smuzhiyun		Shows the total number of write requests issued to the tape
86*4882a593Smuzhiyun		drive.
87*4882a593SmuzhiyunUsers:
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89*4882a593Smuzhiyun
90*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/write_ms
91*4882a593SmuzhiyunDate:           Apr 2015
92*4882a593SmuzhiyunKernelVersion:  4.2
93*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
94*4882a593SmuzhiyunDescription:
95*4882a593Smuzhiyun		Shows the total amount of time in nanoseconds waiting for
96*4882a593Smuzhiyun		write I/O requests to complete.
97*4882a593SmuzhiyunUsers:
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100*4882a593SmuzhiyunWhat:           /sys/class/scsi_tape/*/stats/resid_cnt
101*4882a593SmuzhiyunDate:           Apr 2015
102*4882a593SmuzhiyunKernelVersion:  4.2
103*4882a593SmuzhiyunContact:        Shane Seymour <shane.seymour@hp.com>
104*4882a593SmuzhiyunDescription:
105*4882a593Smuzhiyun		Shows the number of times we found that a residual >0
106*4882a593Smuzhiyun		was found when the SCSI midlayer indicated that there was
107*4882a593Smuzhiyun		an error. For reads this may be a case of someone issuing
108*4882a593Smuzhiyun		reads greater than the block size.
109*4882a593SmuzhiyunUsers:
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