Provided by: sg3-utils_1.46-3ubuntu4_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)
sg3_utils-1.46 July 2020 SG_TURS(8)