Editing Sar

{{lowercase}}
[[Wikipedia: sar (Unix)|sar]] (System Activity Report) is a system utility command used to collect and report different metrics such us [[system load]], CPU activity, [[memory]] (<code>[[/sar -r/]]</code>), paging (<code>sar -B</code>), swap (<code>sar -S</code>), disk ([[sar -d]]), device load and network. It is extremely useful in analyzing current and recent recorded [[system performance]]. Most Linux distributions provide sar utility binary in the <code>sysstat</code> package. You will also find sar in Solaris, AIX, HP-UX but not in MacOs or FreeBSD.

== Installation ==
One line command for installation and basic configuration for collecting :
* Debian/Ubuntu: 
:: <code>apt-get -y install sysstat; [[sed]] -i 's/ENABLED="false"/ENABLED="true"/g' /etc/default/sysstat && service sysstat restart && sar</code>
::Optionally modify collection interval in: <code>/etc/cron.d/sysstat</code>
::Optionally modify collection options in (SADC_OPTIONS="-S XALL"): <code>/etc/sysstat/sysstat</code> (<code>man sadc</code>)
* Redhat/Oracle Linux/AWS AMI: 
:: <code>yum -y install sysstat && service sysstat start</code> 


Installing sar Debian, you have to install sysstat package that includes sar and some other performance tools: 
* <code>[[apt-get]] -y install sysstat</code>
* Checking installation: <code>[[dpkg]] -l sysstat</code>
* Binaries installed in ''/usr/bin/'' directory: <code>dpkg -L sysstat | grep "/usr/bin"</code>. Sysstat package contains sar and some other utilities.
* [[/Installing sysstat using Ansible/]] 
<pre>
/usr/bin/sadc - System Activity Data Collector, a backend to the sar command. Writes binary log of kernel data to the /var/log/sa/saXX file, where the XX parameter indicates the current day
/usr/bin/sadf - System Activity Data Formatter.        Display data collected by sar in multiple formats.
/usr/bin/sar.sysstat  (sar is a symbolink link to this binary)
</pre>
<pre>
/usr/bin/cifsiostat
/usr/bin/iostat
/usr/bin/mpstat
/usr/bin/pidstat
/usr/bin/tapestat
</pre>

* Config files:
 Debian/Ubuntu:
:<code> /etc/default/sysstat</code>
:<code> /etc/cron.d/sysstat</code>    // Collection interval defined in cron configuration
:<code> /etc/sysstat/sysstat</code>
:<code>/etc/sysstat/sysstat.ioconf</code>
::Data directory: <code>/var/log/sysstat</code>

<pre> RedHat
cat /etc/sysconfig/sysstat
cat /etc/cron.d/sysstat
</pre>

== Activation in Debian ==
* To start collection data modify file <code>/etc/default/sysstat</code>, changing text <code>disabled</code> by <code>enabled</code>: <code>vi /etc/default/sysstat</code>
* <code>service sysstat restart</code> (sysstat written with two "ss" do not misspell with systat with just one "s")

Modifying number of days to keep and some other options are done in <code>/etc/sysstat/sysstat</code> file. By default Debian collect files for <code>HISTORY=7</code> 7 days.

== Configuration in Debian/Ubuntu ==
=== Main Configuration file: /etc/sysstat/sysstat ===
<code>/etc/sysstat/sysstat</code> Everything configured in this file, including data collection (sadc) options, except collection interval configured in crontab: <code>/etc/cron.d/sysstat</code>
<pre>
/etc/sysstat/sysstat
HISTORY=7
COMPRESSAFTER=10
SADC_OPTIONS="-S XALL"
SA_DIR=/var/log/sysstat
ZIP="bzip2"
</pre>

By default configuration SADC_OPTIONs is configure to <code>SADC_OPTIONS="-S DISK"</code> you can change SADC_OPTIONS default option to collect all data:
<code> SADC_OPTIONS from ''-S DISK'' to ''-S XALL''</code>. See <code>man sadc</code> for more options: { DISK | INT | IPV6 | POWER | SNMP | XDISK | ALL | XALL [,...] }.

=== Collection interval configuration  ===
To change for every 10 minutes to every 2 minutes or every minute, modify [[cron]] job in file: <code>/etc/cron.d/sysstat</code>
<pre>
5-55/10 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
Every 2 minutes
*/2 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
Every minute
* * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
</pre>

== Usage ==
System activity collection is provided by 4 programs, two binaries <code>sar</code>,<code>sadc</code>  and two shell scripts<code>sa1</code><code>sa2</code>.

Binaries
* <code>/usr/bin/sar</code> -- reporting utility --  it is a link to /usr/bin/sar.sysstat
* <code>/usr/lib64/sa/sadc</code>  -- System activity data collector binary, a backend to the sar command. Writes binary log of kernel data to the /var/log/sa/sadd file, where the dd parameter indicates the current day

Scripts
* <code>/usr/lib64/sa/sa1</code>
* <code>/usr/lib64/sa/sa2</code>

== Basic Usage ==
* Displays collected system activity, execute <code>sar</code>, you will have to wait some time, depending on your configuration, for getting collected information: 
:<code>sar</code>
:<code>sar -A</code> Report all collected date
'''[[Memory]]'''
:<code>[[/sar -r/]]</code>
'''Disk'''
:<code>[[/sar -d/]]</code> To report disk activity. See also <code>[[iostat]] -x</code>.
:<code>[[/sar -F/]]</code> To report disk and [[inodes]] usage. Requires sadc option in <code>/etc/sysstat/sysstat</code> -S XDISK or -S XALL activated.
'''network'''
:<code>sar -n ALL</code> To show '''network''' data collected
'''power management'''
:<code>sar -m ALL</code> To show [[power management]] data collected including [[cpu temperature]] (Requires <code>[[sensors]]/[[lm-sensors]]</code> utility to be installed)

== Activities ==
# Install and configure sar to record system activity every 5 minutes
# Read [[/sysstat changelog/]]: https://github.com/sysstat/sysstat/blob/master/CHANGES

== See also ==
* [[monitoring]]
* [[iostat]], [[iotop]], [[atop]], [[htop]], [[virt-top]], [[fio]]
* <code>[[vmstat]] -d</code>
* [[netdata]], [[MetricBeat]]
* [http://sebastien.godard.pagesperso-orange.fr System Activity Report Homepage]
* isag - [[wikipedia:tcl]] based command to plot sar/sysstat data
* sargraph https://github.com/sysstat/sysstat/blob/master/contrib/sargraph/sargraph2
* [[w:Ksar (Unix sar grapher)]]
* systat [[FreeBSD]]<ref>https://www.freebsd.org/cgi/man.cgi?query=systat&apropos=0&sektion=1&manpath=FreeBSD+Ports+11.2&arch=default&format=html</ref> or NetBSD commands.
* Telegraph https://docs.influxdata.com/telegraf/v1.12/introduction/getting-started/

[[Category:Server administration]]
[[Category:Operating systems]]
[[Category:Linux]]
[[Category:monitoring]]