Ubuntu Manpage: sadc - System activity data collector.

NAME

       sadc - System activity data collector.

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 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.

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.

-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.

-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 { INT | DISK | SNMP | IPV6 | POWER | XDISK | ALL | XALL }
Specify which optional activities should be collected by sadc. Some activities are
optional to prevent data files from growing too large. The INT keyword indicates
that sadc should collect data for system interrupts. The DISK keyword indicates
that sadc should collect data for block devices. The SNMP and IPV6 keywords
indicate respectively that SNMP and IPv6 statistics should be collected by sadc.
The POWER keyword indicates that sadc should collect power management statistics.
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/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  kernel  version  used.
       sadc assumes that you are using at least a 2.6 kernel.

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)