NAME¶
sg_turs - send one or more SCSI TEST UNIT READY commands
SYNOPSIS¶
sg_turs [
--help] [
--number=NUM] [
--progress]
[
--time] [
--verbose] [
--version]
DEVICE
sg_turs [
-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 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.
- -h, --help
- print out the usage message then exit.
- -n, --number=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'.
- -O, --old
- switch to older style options.
- -p, --progress
- show progress indication (a percentage) if available. If
--number=NUM is given, NUM is greater than 1 and an initial
progress indication was detected then this utility waits 30 seconds before
subsequent checks. 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.
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).
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 . In sg3_utils version 1.23 and later these older options can be
selected by either setting the SG3_UTILS_OLD_OPTS environment variable or
using '--old' (or '-O) as the first option.
- -n=NUM
- performs TEST UNIT READY NUM times. If not given
defaults to 1. Equivalent to --number=NUM in the main
description.
- -N
- 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.
AUTHORS¶
Written by D. Gilbert
COPYRIGHT¶
Copyright © 2000-2008 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_request (sg3_utils)