SADC(8)                    (JULY 2020)                    SADC(8)

     NAME
          sadc - System activity data collector.

     SYNOPSIS
          /usr/lib/sysstat/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 for the current day. By default it is
          located in the /var/log/sysstat directory. Yet it is possi-
          ble to specify an alternate location for it: If outfile is a
          directory (instead of a plain file) then it will be consid-
          ered 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 speci-
          fied, 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.

     OPTIONS

     Page 1                        Linux             (printed 5/23/22)

     SADC(8)                    (JULY 2020)                    SADC(8)

          -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 for-
               ward 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,
               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 col-
               lect 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 activi-
               ties are collected.

     Page 2                        Linux             (printed 5/23/22)

     SADC(8)                    (JULY 2020)                    SADC(8)

               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 statis-
               tics. 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 environ-
          ment 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 direc-
               tory.

     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 kernel version used.  sadc assumes that you are using
          at least a 2.6 kernel.

     FILES
          /var/log/sysstat/saDD
          /var/log/sysstat/saYYYYMMDD
               The standard system activity daily data files and their

     Page 3                        Linux             (printed 5/23/22)

     SADC(8)                    (JULY 2020)                    SADC(8)

               default location.

     Page 4                        Linux             (printed 5/23/22)