linux_wiki:sar

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linux_wiki:sar [2014/12/03 21:38]
billdozor 		linux_wiki:sar [2019/05/25 23:50]
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-====== sar (system activity report) ====== 
-sar is used for displaying collected activity counters of various OS stats, including CPU, memory, swap, and disk I/O. 
- 
-sar is a command provided by the sysstat package. 
- 
-===== Installation and Configuration ===== 
-1) Install sysstat (Red Hat or Debian) 
-<code bash> 
-yum install sysstat 
-or 
-apt-get install sysstat 
-</code> 
- 
-2) Enable collection 
-<code bash> 
-vim /etc/default/sysstat 
-</code> 
- 
-Change (Enabled="false") to (Enabled="true"). 
- 
-3) Modify Collection Interval (optional) 
-<code bash> 
-vim /etc/cron.d/sysstat 
-</code> 
- 
-Look for a line like this to edit: 
-# Activity reports every 10 minutes everyday 
-5-55/10 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1 
- 
-4) Start the service 
-<code bash> 
-service sysstat start 
-</code> 
- 
-5) Enable on boot (Red Hat or Debian) 
-<code bash> 
-chkconfig sysstat on 
-or 
-update-rc.d sysstat defaults 
-</code> 
- 
----- 
- 
-===== Usage ===== 
-After sysstat has collected data for a while, you can start to view the information with sar. 
- 
-=== Log location === 
-Sar logs to either: 
-  * /var/log/sysstat/ 
-  * /var/log/sa/ 
- 
-With each log file named after the day of the month it is. 
- 
-Best by visual example: 
-<code bash> 
-ls -l /var/log/sysstat/ 
--rw-r--r-- 1 root root 116880 Dec  1 22:35 sa01 
--rw-r--r-- 1 root root 105984 Dec  2 22:05 sa02 
--rw-r--r-- 1 root root  66032 Dec  3 20:15 sa03 
-</code> 
-These files can be read by sar using the "-f <path-to-file" flag. 
- 
----- 
- 
-=== CPU Utilization === 
-<code bash> 
-sar -u  (displays for current day until that point) 
-sar -u 1 5  (display real time CPU every 1 second, 5 times) 
-sar -u -f /var/log/sysstat/sa01  (display CPU usage on the 1st day of the month) 
-</code> 
- 
-<code bash> 
-Linux 3.13.0-39-generic (dt-bill) 12/03/2014 _x86_64_ (4 CPU) 
- 
-05:22:31 PM       LINUX RESTART 
-05:25:01 PM     CPU     %user     %nice   %system   %iowait    %steal     %idle 
-05:35:01 PM     all      3.70      0.09      0.50      0.56      0.00     95.15 
-05:45:01 PM     all      4.26      0.25      0.62      0.23      0.00     94.64 
-</code> 
- 
-Columns: 
-  * CPU => Which CPU the rest of the columns are about. (Default is all) 
-  * %user => % spent running user level (applications) processes. 
-  * %nice => % spent running user level (applications) with nice priority. 
-  * %system => % spent running at system level. (kernel) 
-  * %iowait => % that CPU(s) were idle while the system was waiting on disk I/O request(s). 
-  * %steal => % spent involutarily waiting by virtual CPU(s) while the hypervisor was servicing another virtual processor. 
-  * %idle => % that CPU(s) were idle and system was not waiting on disk I/O request(s). 
- 
----- 
- 
-=== Memory (RAM) Stats === 
-<code bash> 
-sar -r  (display todays memory stats) 
-sar -r 2 10  (display real time memory stats every 2 seconds, 10 times) 
-</code> 
- 
-sar -r 
-Linux 3.13.0-39-generic (dt-bill) 12/03/2014 _x86_64_ (4 CPU) 
- 
-05:25:01 PM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit  kbactive   kbinact   kbdirty 
-05:35:01 PM   6514076   1661656     20.32     94056    657736   2300940     13.89   1008760    455492       580 
- 
-Columns (probably the only ones you care about): 
-  * kbmemfree => memory free in kilobytes 
-  * kbmemused => memory used in kilobytes 
-  * %memused => % memory used 
- 
----- 
- 
-=== Swap Stats === 
-<code bash> 
-sar -S  (todays swap usage) 
-</code> 
- 
----- 
- 
-=== Disk I/O === 
-<code bash> 
-sar -b  (todays disk usage for block devices) 
-</code> 
- 
----- 
- 
-=== Network Stats === 
-<code bash> 
-sar -n TYPE (todays network statistics) 
-</code> 
- 
-TYPE can be: 
-  * DEV => devices vital stats (eth0, eth1, etc) 
-  * EDEV => device failure stats 
-  * NFS => NFS client activity 
-  * NFSD => NFS server activity 
-  * IP => IPv4 network traffic 
-  * TCP => TCPv4 network traffic 
-  * UDP => UDPv4 network traffic 
-  * ALL => All of the above (and more). Warning: this will be very long. 
- 
----- 
- 
-=== Start and End === 
-<code bash> 
- 
-</code> 
  
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  • Last modified: 2019/05/25 23:50
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