SADC(8) Linux User's Manual SADC(8)NAMEsadc - System activity data collector.
SYNOPSIS
/usr/lib/sa/sadc [ -d ] [ -F ] [ -I ] [ -L ] [ -V ] [ 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 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. By default sadc collects all the
data available from the kernel. Exceptions are interrupts and disks
data, for which the relevant options must be explicitly passed to sadc
(see options below).
When the count parameter is not specified, sadc writes its data end‐
lessly. 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 sys‐
tem 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 com‐
mand.
Note: The sadc command only reports on local activities.
OPTIONS-d Tell sadc to report statistics for disks. By default sadc does
not report disks activity to prevent data files from growing too
large.
-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
interrupts.
-Lsadc 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
file.
-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.
BUGS
/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.
FILES
/var/log/sa/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> wanadoo.fr)
SEE ALSOsar(1), sa1(8), sa2(8), sadf(1), mpstat(1), iostat(1), vmstat(8)
http://perso.orange.fr/sebastien.godard/
Linux JUNE 2006 SADC(8)
