Provided by: sg3-utils_1.46-1build1_amd64 
NAME
sg_turs - send one or more SCSI TEST UNIT READY commands
SYNOPSIS
sg_turs [--delay=MS] [--help] [--low] [--num=NUM] [--number=NUM] [--progress] [--time]
[--verbose] [--version] DEVICE
sg_turs [-d=MS] [-n=NUM] [-p] [-t] [-v] [-V] DEVICE
DESCRIPTION
This utility sends one or more SCSI TEST UNIT READY commands to the DEVICE. This may be
useful for timing the per command overhead. Note that TEST UNIT READY has no associated
data, just a 6 byte command (with each byte a zero) and a returned SCSI status value.
This utility supports two command line syntaxes, the preferred one is shown first in the
synopsis and explained in this section. A later section on the old command line syntax
outlines the second group of options.
OPTIONS
Arguments to long options are mandatory for short options as well.
-d, --delay=MS
this option causes a delay of MS milliseconds to occur before each TEST UNIT READY
command is issued.
-h, --help
print out the usage message then exit.
-l, --low
when [--progress] is not being used, this utility tries to complete the SCSI TEST
UNIT READY command(s) as quickly as possible. Usually it calls a library function
to do each TUR (sg_ll_test_unit_ready). With this option it uses the lower level
sg_pt interface (see sg_pt.h) to save a little time on each TUR.
-n, --num=NUM
performs TEST UNIT READY NUM times. If not given defaults to 1. These suffix
multipliers are permitted: c C *1; w W *2; b B *512; k K KiB *1,024; KB *1,000; m M
MiB *1,048,576; MB *1,000,000; g G GiB *1,073,741,824; and GB *1,000,000,000 . Also
a suffix of the form "x<n>" multiplies the leading number by <n>. Alternatively a
hex number may be given, prefixed by either '0x' or has a trailing 'h'.
--number=NUM
same as --num=NUM. Added for compatibility with sg_requests and other utilities in
this package. The sg_request utility has taken over the role of polling the
progress indication which was originally assigned to the TEST UNIT READY command.
This is a change by T10.
-O, --old
Switch to older style options. Please use as first option.
-p, --progress
show progress indication (a percentage) if available. If --num=NUM is given, NUM is
greater than 1 and an initial progress indication was detected then this utility
waits 30 seconds before subsequent checks. If the --delay=MS option is given then
it will wait for that number of milliseconds instead of 30 seconds. Exits when NUM
is reached or there are no more progress indications. Ignores --time option. See
NOTES section below.
-t, --time
after completing the requested number of TEST UNIT READY commands, outputs the
total duration and the average number of commands executed per second.
-v, --verbose
increase level or verbosity.
-V, --version
print version string then exit.
NOTES
The progress indication is optionally part of the sense data. When a prior command that
takes a long time to complete (and typically precludes other media access commands) is
still underway, the progress indication can be used to determine how long before the
device returns to its normal state. Around SPC-3 T10 changed the preferred command for
polling the progress indication from TEST UNIT READY to REQUEST SENSE (see the sg_requests
utility).
The SCSI FORMAT command for disks used with the IMMED bit set is an example of an
operation that takes a significant amount of time and precludes other media access during
that time. The IMMED bit set instructs the FORMAT command to return control to the
application client once the format has commenced (see SBC-3). Several long duration SCSI
commands associated with tape drives also use the progress indication (see SSC-3).
The DEVICE is opened with a read-only flag (e.g. in Unix with the O_RDONLY flag).
Early standards suggested that the SCSI TEST UNIT READY command be used for polling the
progress indication. More recent standards seem to suggest the SCSI REQUEST SENSE command
should be used instead.
EXIT STATUS
The exit status of sg_turs is 0 when it is successful (e.g. in the case of a mechanical
disk, it is spun up and ready to accept commands). For this utility the other exit status
of interest is 2 corresponding to the "not ready" sense key. For other exit status values
see the sg3_utils(8) man page.
OLDER COMMAND LINE OPTIONS
The options in this section were the only ones available prior to sg3_utils version 1.23 .
Since then this utility defaults to the newer command line options which can be overridden
by using --old (or -O) as the first option. See the ENVIRONMENT VARIABLES section for
another way to force the use of these older command line options.
-d, --delay=MS
this option causes a delay of MS milliseconds to occur before each TEST UNIT READY
command is issued.
-n=NUM performs TEST UNIT READY NUM times. If not given defaults to 1. Equivalent to
--num=NUM in the main description.
-N, --new
Switch to the newer style options.
-p show progress indication (a percentage) if available. Equivalent to --progress in
the main description.
-t after completing the requested number of TEST UNIT READY commands, outputs the
total duration and the average number of commands executed per second. Equivalent
to --time in the main description.
-v increase level of verbosity.
-V print out version string then exit.
ENVIRONMENT VARIABLES
Since sg3_utils version 1.23 the environment variable SG3_UTILS_OLD_OPTS can be given.
When it is present this utility will expect the older command line options. So the
presence of this environment variable is equivalent to using --old (or -O) as the first
command line option.
AUTHORS
Written by D. Gilbert
COPYRIGHT
Copyright © 2000-2020 Douglas Gilbert
This software is distributed under the GPL version 2. There is NO warranty; not even for
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
sg_inq, sg_requests (sg3_utils)