Ubuntu Manpage: sg_turs - send one or more SCSI TEST UNIT READY commands

Provided by: sg3-utils_1.44-1ubuntu2_amd64

NAME

       sg_turs - send one or more SCSI TEST UNIT READY commands

SYNOPSIS

       sg_turs [--help] [--low] [--number=NUM] [--num=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 (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.

-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, --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'.

--num=NUM
same as --number=NUM. Added for compatibility with sg_requests which has taken over the role of
polling the progress indication.

-O, --old
Switch to older style options. Please use as first option.

-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. Around SPC-3
       T10 changed the preferred command for polling the progress indication from TEST  UNIT  READY  to  REQUEST
       SENSE (see the sg_requests utilty).

       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.

       -n=NUM performs TEST UNIT READY NUM times. If not given defaults to 1.  Equivalent to --number=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 © 2000-2018 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.