sadc



SADC(8)                       Linux User’s Manual                      SADC(8)




NAME

       sadc - System activity data collector.


SYNOPSIS

       /usr/lib/sa/sadc  [  -F  ] [ -I ] [ -L ] [ -V ] [ -x pid ] [ -X pid ] [
       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  the  standard
       output.  If  outfile  is  set  to -, then sadc uses the standard system
       activity daily data file,  the  /var/log/sa/sadd  file,  where  the  dd
       parameter  indicates  the current day.  When the count parameter is not
       specified, sadc writes its data  endlessly.   When  both  interval  and
       count  are  not  specified,  a  dummy  record,  which is used at system
       startup to mark the time when the counter  restarts  from  0,  will  be
       written.   For  example, one of the system startup script may write the
       restart mark to the daily data file by the command entry:

       /usr/lib/sa/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.

       -x and -X options are ignored when writing data to a file.



OPTIONS

       -F     The  creation  of  outfile  will  be forced. If the file already
              exists and has not the format expected by sadc then it  will  be
              truncated.  This may be particularly useful for daily data files
              created by an older version of  sadc  and  whose  format  is  no
              longer compatible with current one.

       -I     Tell  sadc  to  report  statistics for all system interrupts. By
              default, sadc only reports statistics for the  total  number  of
              interrupts.

       -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
              might still be running when cron starts a new one. Without lock-
              ing, this situation can result in a  corrupted  system  activity
              file.

       -V     Print version number and usage then exit.

       -x pid Tell sadc to report statistics for the process whose PID is pid.

       -X pid Tell sadc to report statistics for the child  processes  of  the
              process  whose  PID  is  pid.   The  SELF keyword indicates that
              statistics are to be reported for the  child  processes  of  the
              sadc process itself.



EXAMPLES

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


BUGS

       /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.


FILES

       /var/log/sa/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> wanadoo.fr)


SEE ALSO

       sar(1), sa1(8), sa2(8), mpstat(1), iostat(1), vmstat(8)

       http://perso.wanadoo.fr/sebastien.godard/



Linux                              MAY 2004                            SADC(8)

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