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

NAME
       sadc - System activity data collector.


SYNOPSIS
       /usr/lib/sa/sadc [ -C comment ] [ -D ] [ -F ] [ -f ] [ -L ] [ -V ] [ -S
       { keyword[,...] | 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 (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/sa 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/sa/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.


OPTIONS
       -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 name.

       -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.


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/sa directory.


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

       /usr/lib/sa/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
       kernel version used.  sadc assumes that you are using at least a 2.6
       kernel.


FILES
       /var/log/sa/saDD
       /var/log/sa/saYYYYMMDD
	      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.


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


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

       https://github.com/sysstat/sysstat
       https://sysstat.github.io/

Linux				  AUGUST 2023			       SADC(8)