SADC(8) Linux User’s Manual SADC(8)
sadc - System activity data collector.
/usr/lib/sa/sadc [ -F ] [ -I ] [ -L ] [ -V ] [ -x pid ] [ -X pid ] [
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 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:
The sadc command is intended to be used as a backend to the sar com-
Note: The sadc command only reports on local activities.
-x and -X options are ignored when writing data to a file.
-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
-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
-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.
/usr/lib/sa/sadc 1 10 /tmp/datafile
Write 10 records of one second intervals to the /tmp/datafile
/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.
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.
Sebastien Godard (sysstat <at> wanadoo.fr)
sar(1), sa1(8), sa2(8), mpstat(1), iostat(1), vmstat(8)
Linux MAY 2004 SADC(8)
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