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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT | EXAMPLES | BUGS | FILES | AUTHOR | SEE ALSO | COLOPHON |
SADC(8) Linux User's Manual SADC(8)
sadc - System activity data collector.
/usr/local/lib64/sa/sadc [ -C comment ] [ -D ] [ -F ] [ -L ] [ -V ] [
-S { DISK | INT | IPV6 | POWER | SNMP | XDISK | ALL | XALL [,...] } ]
[ 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 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/local/lib64/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.
-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.
-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 { DISK | INT | IPV6 | POWER | SNMP | 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 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.
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.
/usr/local/lib64/sa/sadc 1 10 /tmp/datafile
Write 10 records of one second intervals to the /tmp/datafile
binary file.
/usr/local/lib64/sa/sadc -C Backup_Start /tmp/datafile
Insert the comment Backup_Start into the file /tmp/datafile.
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.
/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.
Sebastien Godard (sysstat <at> orange.fr)
sar(1), sa1(8), sa2(8), sadf(1), sysstat(5)
http://pagesperso-orange.fr/sebastien.godard/
This page is part of the sysstat (sysstat performance monitoring
tools) project. Information about the project can be found at
⟨http://sebastien.godard.pagesperso-orange.fr/⟩. If you have a bug
report for this manual page, send it to systat-AT-orange.fr. This
page was obtained from the project's upstream Git repository
⟨https://github.com/sysstat/sysstat.git⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
Linux DECEMBER 2016 SADC(8)
Pages that refer to this page: sadf(1), sar(1), sysstat(5), sa1(8), sa2(8)