sadc


SYNOPSIS
       /usr/lib/sysstat/sadc  [ -C comment ] [ -F ] [ -L ] [ -V ] [ -S { INT |
       DISK | SNMP | IPV6 | POWER | XDISK | ALL | XALL } ] [ interval [  count
       ] ] [ outfile ]

DESCRIPTION
       The  sadc  command  samples  system  data  a  specified number of times
       (count) at a specified interval  measured  in  seconds  (interval).  It
       writes in binary format to the specified outfile or to standard output.
       If outfile is set to -, then sadc uses  the  standard  system  activity
       daily data file, the /var/log/sysstat/sadd file, where the dd parameter
       indicates the current day.  In this case, sadc will overwrite the  file
       if  it  is from a previous month.  By default sadc collects most of the
       data available from the kernel.  But there are also  optional  metrics,
       for  which the relevant options must be explicitly passed to sadc to be
       collected (see option -S below).

       When the count parameter is not specified, sadc writes  its  data  end-
       lessly.   When both interval and count are not specified, and option -C
       is not used, a dummy record, which is used at system  startup  to  mark
       the  time when the counter restarts from 0, will be written.  For exam-
       ple, one of the system startup script may write the restart mark to the
       daily data file by the command entry:

       /usr/lib/sysstat/sadc -

       The  sadc  command  is intended to be used as a backend to the sar com-
       mand.

       Note: The sadc command only reports on local activities.


OPTIONS
       -C comment
              When neither the interval nor the count  parameters  are  speci-
              fied,  this option tells sadc to write a dummy record containing
              the specified comment string.  This comment  can  then  be  dis-
              played with option -C of sar.

       -F     The  creation  of  outfile  will  be forced. If the file already
              exists and has a format unknown to sadc then it  will  be  trun-
              cated.  This  may  be  useful for daily data files created by an
              older version of sadc and whose format is no  longer  compatible
              with current one.

       -L     sadc  will  try  to  get an exclusive lock on the outfile before
              writing to it or truncating it.  Failure  to  get  the  lock  is
              fatal,  except in the case of trying to write a normal (i.e. not
              a dummy and not a header) record to an existing file,  in  which
              case sadc will try again at the next interval. Usually, the only
              reason a lock would fail would be if another sadc  process  were
              also  writing  to the file. This can happen when cron is used to
              launch sadc.  If the system is under heavy  load,  an  old  sadc
              sadc should collect power management statistics.  The  ALL  key-
              word  is  equivalent  to  specifying  all the keywords above and
              therefore all previous activities are collected.

              The XDISK keyword is an extension to the DISK one and  indicates
              that  partitions  and filesystems statistics should be collected
              by sadc in addition to disk statistics. This option  works  only
              with  kernels  2.6.25 and later.  The XALL keyword is equivalent
              to specifying all the keywords above (including  keyword  exten-
              sions) and therefore all possible activities are collected.

              Important  note:  The activities (including optional ones) saved
              in an existing data file prevail over those selected with option
              -S.   As  a consequence, appending data to an existing data file
              will result in option -S being ignored.

       -V     Print version number then exit.


ENVIRONMENT
       The sadc command takes into account the following environment variable:


       S_TIME_DEF_TIME
              If this variable exists and its value is UTC then sadc will save
              its  data  in  UTC time.  sadc will also use UTC time instead of
              local time to determine the current daily data file  located  in
              the /var/log/sysstat directory.

EXAMPLES
       /usr/lib/sysstat/sadc 1 10 /tmp/datafile
              Write  10  records  of one second intervals to the /tmp/datafile
              binary file.

       /usr/lib/sysstat/sadc -C Backup_Start /tmp/datafile
              Insert the comment Backup_Start into the file /tmp/datafile.

BUGS
       The /proc filesystem must be mounted for the sadc command to work.

       All the statistics are not necessarily available, depending on the ker-
       nel  version used.  sadc assumes that you are using at least a 2.6 ker-
       nel.

FILES
       /var/log/sysstat/sadd
              Indicate the daily data file, where the dd parameter is a number
              representing the day of the month.

       /proc contains various files with system statistics.

AUTHOR
       Sebastien Godard (sysstat <at> orange.fr)
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