How to Setup Sar (Sysstat) – Monitor Linux System Performance

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Sysstat contains various utilities to collect and historize performance and monitor server activity on the linux. Sar is part of the sysstat package. by using sar, we can collect, report, or save system resource utilization information. It will help system administrator to troubleshoot performance issues, or to optimize performance. This post will show how to setup and the usage of sar on linux CentOS 6.5.

1. Install sar (systat) :

[[email protected] ~]# yum install sysstat -y

2. Verify the sar version using “sar -V”

[[email protected] ~]# sar -V
sysstat version 9.0.4
(C) Sebastien Godard (sysstat  orange.fr)

3. Sar usage examples :

a) Check swap usage :

[[email protected] ~]# sar -W
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:10:01 PM  pswpin/s pswpout/s
11:20:01 PM      0.00      0.00
11:30:01 PM      0.00      0.00
11:40:01 PM      0.00      0.00
Average:         0.00      0.00

b) Check system load :

[[email protected] ~]# sar -q
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:10:01 PM   runq-sz  plist-sz   ldavg-1   ldavg-5  ldavg-15
11:20:01 PM         0        86      0.00      0.00      0.00
11:30:01 PM         0        85      0.00      0.00      0.00
11:40:01 PM         0        85      0.00      0.00      0.00
Average:            0        85      0.00      0.00      0.00

c) Collect CPU statistics 3 times within 1 second interval :

[[email protected] ~]# sar 1 3
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:46:55 PM     CPU     %user     %nice   %system   %iowait    %steal     %idle
11:46:56 PM     all      0.00      0.00      0.50      0.00      0.00     99.50
11:46:57 PM     all      0.00      0.00      0.00      0.00      0.00    100.00
11:46:58 PM     all      0.00      0.00      0.00      0.00      0.00    100.00
Average:        all      0.00      0.00      0.17      0.00      0.00     99.83

d) Displaying the RAM Load:

[[email protected] ~]# sar -r
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:10:01 PM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit
11:20:01 PM   3670608    254080      6.47     11872    160172     67684      1.12
11:30:01 PM   3670616    254072      6.47     11892    160172     67684      1.12
11:40:01 PM   3670508    254180      6.48     11920    160180     67684      1.12
Average:      3670577    254111      6.47     11895    160175     67684      1.12

e) Display paging statistic :

[[email protected] ~]# sar -B
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:10:01 PM  pgpgin/s pgpgout/s   fault/s  majflt/s  pgfree/s pgscank/s pgscand/s pgsteal/s    %vmeff
11:20:01 PM      0.00      0.23      8.21      0.00      4.36      0.00      0.00      0.00      0.00
11:30:01 PM      0.00      0.19      2.70      0.00      1.29      0.00      0.00      0.00      0.00
11:40:01 PM      0.00      0.14      3.75      0.00      1.62      0.00      0.00      0.00      0.00
11:50:01 PM      0.00      0.16      6.60      0.00      2.80      0.00      0.00      0.00      0.00
Average:         0.00      0.18      5.31      0.00      2.52      0.00      0.00      0.00      0.00

f) Display Swap space utilization statistics :

[[email protected] ~]# sar -S
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/18/2014      _x86_64_        (2 CPU)

11:10:01 PM kbswpfree kbswpused  %swpused  kbswpcad   %swpcad
11:20:01 PM   2097144         0      0.00         0      0.00
11:30:01 PM   2097144         0      0.00         0      0.00
11:40:01 PM   2097144         0      0.00         0      0.00
11:50:01 PM   2097144         0      0.00         0      0.00
Average:      2097144         0      0.00         0      0.00

4. Monitor previous day sar statictics :

Every sar statictics by default stored in /var/log/sa. Es example :

[[email protected] sa]# ls
sa18  sa19  sa20  sa21  sa22  sa23  sa24  sar18  sar19  sar20  sar23

a. Display cpu load on sa22 :

[[email protected] sa]# sar -f /var/log/sa/sa22
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/22/2014      _x86_64_        (2 CPU)

12:00:01 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle
12:10:01 AM     all      0.04      0.00      0.06      0.06      0.00     99.84
12:20:01 AM     all      0.03      0.00      0.05      0.07      0.00     99.85
12:30:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
12:40:01 AM     all      0.34      0.00      0.71      0.02      0.00     98.93
12:50:01 AM     all      1.67      0.00      3.19      0.01      0.00     95.13
01:00:01 AM     all      0.64      0.00      0.83      0.74      0.00     97.79
01:10:01 AM     all      0.64      0.00      1.51      0.03      0.00     97.83
01:20:01 AM     all      0.35      0.00      0.71      0.13      0.00     98.81
01:30:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
01:40:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
01:50:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.91
02:00:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
02:10:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
02:20:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
02:30:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
02:40:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
02:50:01 AM     all      0.03      0.00      0.04      0.01      0.00     99.92
03:00:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.92
03:10:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
03:20:01 AM     all      0.03      0.00      0.04      0.01      0.00     99.92
03:30:01 AM     all      0.03      0.00      0.04      0.01      0.00     99.92
03:40:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.91
03:50:01 AM     all      0.03      0.00      0.05      0.03      0.00     99.89
04:00:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
04:10:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
04:20:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.92
04:30:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
04:40:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
04:50:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91
05:00:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.92
05:10:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
05:20:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.91
05:30:01 AM     all      0.03      0.00      0.04      0.02      0.00     99.91

05:30:01 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle
05:40:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
05:50:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
06:00:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.91
06:10:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.90
06:20:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
06:30:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
06:40:02 AM     all      0.03      0.00      0.05      0.01      0.00     99.92
06:50:01 AM     all      0.03      0.00      0.04      0.01      0.00     99.92
07:00:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
07:10:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
07:20:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.92
07:30:01 AM     all      0.03      0.00      0.04      0.01      0.00     99.92
07:40:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
07:50:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
08:00:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
08:10:01 AM     all      0.03      0.00      0.05      0.02      0.00     99.90
08:20:01 AM     all      0.03      0.00      0.05      0.01      0.00     99.91
Average:        all      0.10      0.00      0.18      0.03      0.00     99.69

b. Display RAM Load on sa22 :

[[email protected] sa]# sar -f /var/log/sa/sa22 -r
Linux 2.6.32-431.el6.x86_64 (oss.ehowstuff.local)       08/22/2014      _x86_64_        (2 CPU)

12:00:01 AM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit
12:10:01 AM   3807336    117352      2.99      8252     32352     66920      1.11
12:20:01 AM   3804708    119980      3.06      8712     32812     71440      1.19
12:30:01 AM   3804584    120104      3.06      8744     32816     71592      1.19
12:40:01 AM   3799784    124904      3.18      8768     33124     72228      1.20
12:50:01 AM   3799668    125020      3.19      8800     33124     72228      1.20
01:00:01 AM   3723612    201076      5.12     10048    110608     71592      1.19
01:10:01 AM   3718804    205884      5.25     10232    111044     72228      1.20
01:20:01 AM   3711560    213128      5.43     10284    122396     71592      1.19
01:30:01 AM   3711684    213004      5.43     10324    122408     71592      1.19
01:40:01 AM   3711436    213252      5.43     10348    122408     71592      1.19
01:50:01 AM   3711436    213252      5.43     10372    122412     71592      1.19
02:00:01 AM   3711560    213128      5.43     10404    122416     71592      1.19
02:10:01 AM   3711576    213112      5.43     10444    122424     71592      1.19
02:20:01 AM   3711568    213120      5.43     10476    122428     71592      1.19
02:30:01 AM   3711444    213244      5.43     10516    122436     71592      1.19
02:40:01 AM   3711320    213368      5.44     10552    122436     71592      1.19
02:50:01 AM   3711320    213368      5.44     10580    122444     71592      1.19
03:00:01 AM   3711188    213500      5.44     10612    122448     71592      1.19
03:10:01 AM   3711180    213508      5.44     10652    122456     72168      1.20
03:20:01 AM   3711180    213508      5.44     10676    122456     72168      1.20
03:30:01 AM   3710932    213756      5.45     10708    122464     72168      1.20
03:40:01 AM   3710692    213996      5.45     10740    122464     72168      1.20
03:50:01 AM   3710700    213988      5.45     10928    122604     71592      1.19
04:00:01 AM   3710568    214120      5.46     10960    122608     71592      1.19
04:10:01 AM   3710816    213872      5.45     11000    122608     71592      1.19
04:20:01 AM   3710576    214112      5.46     11032    122616     71592      1.19
04:30:01 AM   3710576    214112      5.46     11068    122616     71592      1.19
04:40:01 AM   3710708    213980      5.45     11096    122624     71592      1.19
04:50:01 AM   3710452    214236      5.46     11128    122628     71592      1.19
05:00:01 AM   3710576    214112      5.46     11160    122636     71592      1.19
05:10:01 AM   3710452    214236      5.46     11200    122636     71592      1.19
05:20:01 AM   3710576    214112      5.46     11232    122644     71592      1.19
05:30:01 AM   3710708    213980      5.45     11268    122644     71592      1.19

05:30:01 AM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit
05:40:01 AM   3710320    214368      5.46     11296    122652     71592      1.19
05:50:01 AM   3710072    214616      5.47     11320    122652     71592      1.19
06:00:01 AM   3710204    214484      5.46     11364    122660     71592      1.19
06:10:01 AM   3710072    214616      5.47     11400    122664     71592      1.19
06:20:01 AM   3710204    214484      5.46     11424    122668     71592      1.19
06:30:01 AM   3710204    214484      5.46     11464    122676     71592      1.19
06:40:02 AM   3709948    214740      5.47     11488    122680     71592      1.19
06:50:01 AM   3710072    214616      5.47     11512    122680     71592      1.19
07:00:01 AM   3710204    214484      5.46     11552    122680     71592      1.19
07:10:01 AM   3709824    214864      5.47     11584    122692     71592      1.19
07:20:01 AM   3709948    214740      5.47     11612    122688     71592      1.19
07:30:01 AM   3709956    214732      5.47     11648    122700     71592      1.19
07:40:01 AM   3709956    214732      5.47     11680    122704     71592      1.19
07:50:01 AM   3709824    214864      5.47     11704    122708     71592      1.19
08:00:01 AM   3709832    214856      5.47     11744    122712     71592      1.19
08:10:01 AM   3709700    214988      5.48     11784    122724     71592      1.19
08:20:01 AM   3709700    214988      5.48     11812    122720     71592      1.19
Average:      3720306    204382      5.21     10794    113138     71580      1.19

5. Other sar options :

[[email protected] ~]# sar -h
Usage: sar [ options ] [  [  ] ]
Main options and reports:
        -b      I/O and transfer rate statistics
        -B      Paging statistics
        -d      Block device statistics
        -I {  | SUM | ALL | XALL }
                Interrupts statistics
        -m      Power management statistics
        -n {  [,...] | ALL }
                Network statistics
                Keywords are:
                DEV     Network interfaces
                EDEV    Network interfaces (errors)
                NFS     NFS client
                NFSD    NFS server
                SOCK    Sockets (v4)
                IP      IP traffic      (v4)
                EIP     IP traffic      (v4) (errors)
                ICMP    ICMP traffic    (v4)
                EICMP   ICMP traffic    (v4) (errors)
                TCP     TCP traffic     (v4)
                ETCP    TCP traffic     (v4) (errors)
                UDP     UDP traffic     (v4)
                SOCK6   Sockets (v6)
                IP6     IP traffic      (v6)
                EIP6    IP traffic      (v6) (errors)
                ICMP6   ICMP traffic    (v6)
                EICMP6  ICMP traffic    (v6) (errors)
                UDP6    UDP traffic     (v6)
        -q      Queue length and load average statistics
        -r      Memory utilization statistics
        -R      Memory statistics
        -S      Swap space utilization statistics
        -u [ ALL ]
                CPU utilization statistics
        -v      Kernel table statistics
        -w      Task creation and system switching statistics
        -W      Swapping statistics
        -y      TTY device statistics

6. Other sysstat utilities:

sar collects and displays ALL system activities statistics.
sadc stands for “system activity data collector”. This is the sar backend tool that does the data collection.
sa1 stores system activities in binary data file. sa1 depends on sadc for this purpose. sa1 runs from cron.
sa2 creates daily summary of the collected statistics. sa2 runs from cron.
sadf can generate sar report in CSV, XML, and various other formats. Use this to integrate sar data with other tools.
iostat generates CPU, I/O statistics
mpstat displays CPU statistics.
pidstat reports statistics based on the process id (PID)
nfsiostat displays NFS I/O statistics.
cifsiostat generates CIFS statistics.

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