Provided by: sysstat_12.5.6-1_amd64 bug


       sadc - System activity data collector.


       /usr/lib/sysstat/sadc  [  -C  comment  ]  [  -D  ]  [  -F  ]  [  -f ] [ -L ] [ -V ] [ -S {
       keyword[,...] | ALL | XALL } ] [ interval [ count ] ] [ outfile ]


       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 (see below).  In this case, if the file already exists, sadc will
       overwrite it 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).

       The standard system activity daily data file is named saDD unless option -D  is  used,  in
       which  case  its  name  is  saYYYYMMDD, where YYYY stands for the current year, MM for the
       current month and DD for the current day. By default it is located in the /var/log/sysstat
       directory.  Yet  it  is  possible to specify an alternate location for it: If outfile is a
       directory (instead of a plain file) then it will be considered as the directory where  the
       standard system activity daily data file will be saved.

       When  the  count  parameter  is  not  specified, sadc writes its data endlessly. 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 example, 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 command.

       Note: The sadc command only reports on local activities.


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

       -D     Use  saYYYYMMDD  instead  of  saDD  as the standard system activity daily data file

       -F     The creation of outfile will be forced. If the file already exists and has a format
              unknown  to sadc then it will be truncated. 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.

       -f     fdatasync()  will  be used to ensure data is written to disk. This differs from the
              normal operation in that a sudden system reset is less likely to result in the saDD
              datafiles  being  corrupted.  However, this is at the expense of performance within
              the sadc process as forward progress will be  blocked  while  data  is  written  to
              underlying disk instead of just to cache.

       -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
              locking, this situation can result in a corrupted system activity file.

       -S { keyword[,...] | ALL | XALL }
              Possible keywords are DISK, INT, IPV6, POWER, SNMP, XDISK, ALL and XALL.
              Specify which optional activities should be collected by sadc.  Some activities are
              optional  to  prevent data files from growing too large. The DISK keyword indicates
              that sadc should collect data for block devices. The  INT  keyword  indicates  that
              sadc  should  collect  data  for system interrupts. The IPV6 keyword indicates that
              IPv6 statistics should be collected by sadc. The POWER keyword indicates that  sadc
              should  collect  power  management statistics. The SNMP keyword indicates that SNMP
              statistics should be collected by sadc. The ALL keyword 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 extensions)  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.


       The sadc command takes into account the following environment variable:

              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.


       /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.


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

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


              The standard system activity daily data files and  their  default  location.   YYYY
              stands for the current year, MM for the current month and DD for the current day.
       /proc and /sys contain various files with system statistics.


       Sebastien Godard (sysstat <at>


       sar(1), sa1(8), sa2(8), sadf(1), sysstat(5)