1SG_TURS(8) SG3_UTILS SG_TURS(8)
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6 sg_turs - send one or more SCSI TEST UNIT READY commands
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9 sg_turs [--help] [--low] [--num=NUM] [--number=NUM] [--progress]
10 [--time] [--verbose] [--version] DEVICE
11 sg_turs [-n=NUM] [-p] [-t] [-v] [-V] DEVICE
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15 This utility sends one or more SCSI TEST UNIT READY commands to the
16 DEVICE. This may be useful for timing the per command overhead. Note
17 that TEST UNIT READY has no associated data, just a 6 byte command
18 (with each byte a zero) and a returned SCSI status value.
19 This utility supports two command line syntaxes, the preferred one is
21 shown first in the synopsis and explained in this section. A later sec‐
22 tion on the old command line syntax outlines the second group of
23 options.
24
26 Arguments to long options are mandatory for short options as well.
27 -h, --help
29 print out the usage message then exit.
30 -l, --low
32 when [--progress] is not being used, this utility tries to com‐
33 plete the SCSI TEST UNIT READY command(s) as quickly as possi‐
34 ble. Usually it calls a library function to do each TUR
35 (sg_ll_test_unit_ready). With this option it uses the lower
36 level sg_pt interface (see sg_pt.h) to save a little time on
37 each TUR.
38 -n, --num=NUM
40 performs TEST UNIT READY NUM times. If not given defaults to 1.
41 These suffix multipliers are permitted: c C *1; w W *2; b B
42 *512; k K KiB *1,024; KB *1,000; m M MiB *1,048,576; MB
43 *1,000,000; g G GiB *1,073,741,824; and GB *1,000,000,000 . Also
44 a suffix of the form "x<n>" multiplies the leading number by
45 <n>. Alternatively a hex number may be given, prefixed by either
46 '0x' or has a trailing 'h'.
47 --number=NUM
49 same as --num=NUM. Added for compatibility with sg_requests and
50 other utilities in this package. The sg_request utility has
51 taken over the role of polling the progress indication which was
52 originally assigned to the TEST UNIT READY command. This is a
53 change by T10.
54 -O, --old
56 Switch to older style options. Please use as first option.
57 -p, --progress
59 show progress indication (a percentage) if available. If
60 --num=NUM is given, NUM is greater than 1 and an initial
61 progress indication was detected then this utility waits 30 sec‐
62 onds before subsequent checks. Exits when NUM is reached or
63 there are no more progress indications. Ignores --time option.
64 See NOTES section below.
65 -t, --time
67 after completing the requested number of TEST UNIT READY com‐
68 mands, outputs the total duration and the average number of com‐
69 mands executed per second.
70 -v, --verbose
72 increase level or verbosity.
73 -V, --version
75 print version string then exit.
76
78 The progress indication is optionally part of the sense data. When a
79 prior command that takes a long time to complete (and typically pre‐
80 cludes other media access commands) is still underway, the progress
81 indication can be used to determine how long before the device returns
82 to its normal state. Around SPC-3 T10 changed the preferred command for
83 polling the progress indication from TEST UNIT READY to REQUEST SENSE
84 (see the sg_requests utilty).
85 The SCSI FORMAT command for disks used with the IMMED bit set is an
87 example of an operation that takes a significant amount of time and
88 precludes other media access during that time. The IMMED bit set
89 instructs the FORMAT command to return control to the application
90 client once the format has commenced (see SBC-3). Several long duration
91 SCSI commands associated with tape drives also use the progress indica‐
92 tion (see SSC-3).
93 The DEVICE is opened with a read-only flag (e.g. in Unix with the
95 O_RDONLY flag).
96 Early standards suggested that the SCSI TEST UNIT READY command be used
98 for polling the progress indication. More recent standards seem to sug‐
99 gest the SCSI REQUEST SENSE command should be used instead.
100
102 The exit status of sg_turs is 0 when it is successful (e.g. in the case
103 of a mechanical disk, it is spun up and ready to accept commands). For
104 this utility the other exit status of interest is 2 corresponding to
105 the "not ready" sense key. For other exit status values see the
106 sg3_utils(8) man page.
107
109 The options in this section were the only ones available prior to
110 sg3_utils version 1.23 . Since then this utility defaults to the newer
111 command line options which can be overridden by using --old (or -O) as
112 the first option. See the ENVIRONMENT VARIABLES section for another way
113 to force the use of these older command line options.
114 -n=NUM performs TEST UNIT READY NUM times. If not given defaults to 1.
116 Equivalent to --num=NUM in the main description.
117 -N, --new
119 Switch to the newer style options.
120 -p show progress indication (a percentage) if available. Equiva‐
122 lent to --progress in the main description.
123 -t after completing the requested number of TEST UNIT READY com‐
125 mands, outputs the total duration and the average number of com‐
126 mands executed per second. Equivalent to --time in the main
127 description.
128 -v increase level of verbosity.
130 -V print out version string then exit.
132
134 Since sg3_utils version 1.23 the environment variable
135 SG3_UTILS_OLD_OPTS can be given. When it is present this utility will
136 expect the older command line options. So the presence of this environ‐
137 ment variable is equivalent to using --old (or -O) as the first command
138 line option.
139
141 Written by D. Gilbert
142
144 Copyright © 2000-2019 Douglas Gilbert
145 This software is distributed under the GPL version 2. There is NO war‐
146 ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR‐
147 POSE.
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150 sg_inq, sg_requests (sg3_utils)
151sg3_utils-1.45 September 2019 SG_TURS(8)