Ubuntu Manpage: sg_timestamp - report or set timestamp on SCSI device

Provided by: sg3-utils_1.46-1build1_amd64

NAME

       sg_timestamp - report or set timestamp on SCSI device

SYNOPSIS

       sg_timestamp  [--elapsed] [--help] [--hex] [--milliseconds=MS] [--no-timestamp] [--origin]
       [--raw] [--readonly] [--seconds=SECS] [--srep] [--verbose] [--version] DEVICE

DESCRIPTION

       Sends a SCSI REPORT TIMESTAMP or SET TIMESTAMP command to the DEVICE.  These commands  are
       found in the SPC-5 draft standard revision 7 (spc5r07.pdf).

       If  either  the  --milliseconds=MS  or  --seconds=SECS  option is given (and both can't be
       given) then the SET TIMESTAMP command is sent; otherwise the REPORT TIMESTAMP  command  is
       sent.

       The timestamp is sent and received from the DEVICE as the number of milliseconds since the
       epoch of 1970-01-01 00:00:00 UTC and is held in a 48 bit unsigned integer. That same epoch
       is  used  by  Unix machines, but they usually hold the number of seconds since that epoch.
       The Unix date command and especially its "+%s" format is useful in converting to and  from
       timestamps and more humanly readable forms. See the EXAMPLES section below.

OPTIONS

Arguments to long options are mandatory for short options as well.

-e, --elapsed
assume the timestamp in the REPORT TIMESTAMP is an elapsed time from an event such
as a power cycle or hard reset and format the output as '<n> days hh:mm:ss.xxx'
where hh is hours (00 to 23 inclusive); mm is minutes (00 to 59 inclusive); ss is
seconds (00 to 59 inclusive) and xxx is milliseconds (000 to 999 inclusive). If the
number of days is 0 then '0 days' is not output unless this option is given two or
more times.

-h, --help
output the usage message then exit.

-H, --hex
output the response to REPORT TIMESTAMP in ASCII hexadecimal on stderr. The
response is not decoded.

-m, --milliseconds=MS
where MS is the number of milliseconds since 1970-01-01 00:00:00 UTC to set in the
DEVICE with the SCSI SET TIMESTAMP command.

-N, --no-timestamp
when REPORT TIMESTAMP is called this option suppress the output of the timestamp
value (in either seconds or milliseconds). This may be useful in uncluttering the
output when trying to decode the timestamp origin (see the --origin option).

-o, --origin
the REPORT TIMESTAMP returned parameter data contains a "timestamp origin" field.
When this option is given, that field is decoded and printed out before the
timestamp value is output. The default action (i.e. when the option is not given)
is not to print out this decoded field.
T10 defines this field as "the most recent event that initialized the returned
device clock". The value 0 indicates a power up of hard reset initialized the
clock; 2 indicates a SET TIMESTAMP initialized the clock while 3 indicates some
other method initialized the clock.
When used once a descriptive string is output (in a line before the timestamp
value). When used twice the value of the TIMESTAMP ORIGIN field is output (in
decimal, a value between 0 and 7 inclusive). When used thrice a line of the form
'TIMESTAMP_ORIGIN=<value>' is output.

-r, --raw
output the SCSI REPORT TIMESTAMP response (i.e. the data-out buffer) in binary (to
stdout). Note that the --origin and --srep options are ignored when this option is
given. Also all error and verbose messages are output to stderr.

-R, --readonly
open the DEVICE read-only. The default action is to open the DEVICE read-write.

-s, --seconds=SECS
where SECS is the number of seconds since 1970-01-01 00:00:00 UTC to set in the
DEVICE with the SCSI SET TIMESTAMP command. SECS is multiplied by 1000 before being
used in the SET TIMESTAMP command.

-S, --srep
report the number of seconds since 1970-01-01 00:00:00 UTC. This is done by
dividing by 1000 the value returned by the SCSI REPORT TIMESTAMP command.

-v, --verbose
increase the level of verbosity, (i.e. debug output).

-V, --version
print the version string and then exit.

EXIT STATUS

       The exit status of sg_timestamp is 0 when it is successful. Otherwise see the sg3_utils(8)
       man page.

NOTES

       The  TCMOS  and  the SCSIP bits in the Control extension mode page (see sdparm) modify the
       actions of the timestamp held by a DEVICE.

       Currently only the "Utilization usage rate based on date and time" parameters  within  the
       Utilization  log  page  (sbc4r09.pdf)  use  timestamps.  See  the  sg_logs utility. Vendor
       specific commands and pages may also be using timestamps.

EXAMPLES

       On Unix machines (e.g. Linux, FreeBSD and Solaris) the date command is useful when working
       with timestamps.

       To  fetch  the  timestamp  from  a  DEVICE  and  display it in a humanly readable form the
       following could be used:

          # sg_timestamp -S /dev/sdb
       1448993950
          # date --date=@1448993950
       Tue Dec  1 13:19:10 EST 2015
          # date -R --date="@1448993950"
       Tue, 01 Dec 2015 13:19:10 -0500

       The latter two date commands show different forms  of  the  same  date  (i.e.   1448993950
       seconds since 1970-01-01 00:00:00 UTC). The sg_timestamp and date commands can be combined
       using backquotes:

          # date -R --date=@`sg_timestamp -S /dev/sdc`
       Wed, 16 Dec 2015 20:12:59 -0500

       To set the timestamp on the DEVICE to now (approximately) the following could be used:

          # date +%s
       1448993955
          # sg_timestamp --seconds=1448993955 /dev/sdb

       Those two command lines could be combined into one by using backquotes:

          # sg_timestamp --seconds=`date +%s` /dev/sdb

AUTHORS

       Written by Douglas Gilbert.

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright © 2015-2018 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not  even  for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.