====== sar ======
---- dataentry analysisTool ----
name : sar
features_ttags : monitoring
layers_ttags : application, operating system, block device, network
version : 11.2.1.1 (2016-02-21)
webpage_url : http://sebastien.godard.pagesperso-orange.fr/
license_ttag : GPLv2
----
Sar is part of Sysstat, a collection of performance monitoring tools for Linux.
===== Usage =====
Run ''sar 2'' where interval in seconds measurements will taken shown at. sar outputs a variety of performance data. See the man page for information on all of the available diagnostics. For monitoring I/O you may use the ''-b'' or ''-d'' flags to view I/O transfer rates or block device activity respectively.
The feature that sets sar apart from tools like [[tools:analysis:iotop:|iotop]] is it's logging capability. Once logging is set up you may use ''sar -A'' to view all information in the current days logfile or use ''-f'' to specify a specific logfile you want to examine.
==== Logging Setup ====
To make use of sar you first need to enable logging. When building from source ''make install --enable-install-cron'' can be used to enable logging via [[https://en.wikipedia.org/wiki/Cron|cron]]. When installing a package, depending on your distribution, logging might be enabled by default or you may have to use either your init-system or create a cron-job to activate it. For details view the [[http://sebastien.godard.pagesperso-orange.fr/documentation.html|sysstat-documentation]] or the relevant documentation for your distribution.
===== Output =====
The default output when running ''sar'' looks like this:
Linux 4.4.3-1-ARCH (your-hostname) 03/10/2016 _x86_64_ (8 CPU)
02:52:49 PM CPU %user %nice %system %iowait %steal %idle
02:52:51 PM all 8.02 0.00 1.13 0.00 0.00 90.86
02:52:53 PM all 8.57 0.00 0.69 0.06 0.00 90.68
02:52:55 PM all 8.43 0.00 1.00 0.00 0.00 90.57
02:52:57 PM all 7.66 0.00 0.69 0.00 0.00 91.65
''sar -bd 2'' results in this output:
Linux 4.4.3-1-ARCH (your-hostname) 03/10/2016 _x86_64_ (8 CPU)
03:25:29 PM tps rtps wtps bread/s bwrtn/s
03:25:31 PM 59.00 0.00 59.00 0.00 47068.00
03:25:29 PM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
03:25:31 PM dev8-0 59.00 0.00 47068.00 797.76 2.24 37.91 0.76 4.50
03:25:31 PM dev8-32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
03:25:31 PM dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
03:25:31 PM tps rtps wtps bread/s bwrtn/s
03:25:33 PM 1.00 0.00 1.00 0.00 52.00
03:25:31 PM DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util
03:25:33 PM dev8-0 1.00 0.00 52.00 52.00 0.00 0.00 0.00 0.00
03:25:33 PM dev8-32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
03:25:33 PM dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
===== Similar tools =====
---- datarelated ----
cols : features, layers
max : 5
sort : ^name
----