Installing and configuring sysstat on CentOS 8
This article shows how to install sysstat and to check the system.
# yum -y install sysstat
Calling the system activity data collector (sadc):
# systemctl enable sysstat
[2] The jobs getting system information are set like follows. Logs are stored in “/var/log/sa/sa**” and “/var/log/sa/sar**”.
# cat /etc/cron.d/sysstat
# Run system activity accounting tool every 10 minutes */10 * * * * root /usr/lib64/sa/sa1 1 1 # 0 * * * * root /usr/lib64/sa/sa1 600 6 & # Generate a daily summary of process accounting at 23:53 53 23 * * * root /usr/lib64/sa/sa2 -A
Check that sysstat is enabled.
# nano /etc/default/sysstat # # Default settings for /etc/init.d/sysstat, /etc/cron.d/sysstat # and /etc/cron.daily/sysstat files # # Should sadc collect system activity informations? Valid values # are "true" and "false". Please do not put other values, they # will be overwritten by debconf! ENABLED="false"
Change ENABLED=”false” to ENABLED=”true”. Then startsysstat
# systemctl start sysstat
View RAM usage
# sar -r 12:00:01 AM kbmemfree kbmemused %memused kbbuffers kbcached kbcommit %commit 12:10:01 AM 419648 1502728 78.17 66732 397336 1376580 38.26 12:20:01 AM 419276 1503100 78.19 66984 397428 1376580 38.26 12:30:01 AM 419152 1503224 78.20 67196 397488 1376580 38.26 12:40:01 AM 418904 1503472 78.21 67316 397528 1376580 38.26
view Swap usage
sar -S 12:00:01 AM kbswpfree kbswpused %swpused kbswpcad %swpcad 12:10:01 AM 1607192 68068 4.06 8468 12.44 12:20:01 AM 1607196 68064 4.06 8464 12.44 12:30:01 AM 1607200 68060 4.06 8460 12.43 12:40:01 AM 1607208 68052 4.06 8464 12.44
It’s possible to output current or past status of system with “sar” command like follows.
[3] Output the past CPU usage from the log file.
[root@dlp ~]# sar -u -f /var/log/sa/sa24
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/24/2013 _x86_64_ (2 CPU) 04:45:47 AM LINUX RESTART 01:50:01 PM CPU %user %nice %system %iowait %steal %idle 01:59:03 PM all 0.00 0.00 0.02 0.09 0.00 99.89 02:00:01 PM all 0.02 0.00 0.07 0.29 0.02 99.60 02:10:01 PM all 0.00 0.00 0.01 0.05 0.00 99.94 02:20:01 PM all 0.00 0.00 0.00 0.01 0.00 99.99 02:30:01 PM all 0.00 0.00 0.00 0.01 0.00 99.99 02:40:01 PM all 0.00 0.30 0.50 0.36 0.00 98.84 02:50:01 PM all 0.00 0.00 0.00 0.02 0.00 99.98 03:00:01 PM all 0.00 0.00 0.00 0.02 0.00 99.98 03:10:01 PM all 0.00 0.00 0.00 0.04 0.00 99.95 Average: all 0.00 0.04 0.07 0.08 0.00 99.82 03:19:29 PM LINUX RESTART ... ...
[4] Output the current CPU usage for 3 times every second.
[root@dlp ~]# sar -u 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/24/2013 _x86_64_ (2 CPU) 05:29:12 PM CPU %user %nice %system %iowait %steal %idle 05:29:13 PM all 0.00 0.00 0.00 0.00 0.00 100.00 05:29:14 PM all 0.00 0.00 0.00 0.00 0.50 99.50 05:29:15 PM all 0.50 0.00 0.50 0.00 0.00 99.00 Average: all 0.17 0.00 0.17 0.00 0.17 99.50
[5] Output the current Disk usage for 3 times every second.
[root@dlp ~]#sar -b 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 06:02:27 AM tps rtps wtps bread/s bwrtn/s 06:02:28 AM 0.00 0.00 0.00 0.00 0.00 06:02:29 AM 0.00 0.00 0.00 0.00 0.00 06:02:30 AM 0.00 0.00 0.00 0.00 0.00 Average: 0.00 0.00 0.00 0.00 0.00
[6] Output the current Memory usage for 3 times every second.
[root@dlp ~]# sar -r 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 03:06:52 PM kbmemfree kbmemused %memused kbbuffers kbcached kbcommit %commit 03:06:53 PM 1832648 89916 4.68 5796 24552 53452 0.88 03:06:54 PM 1832648 89916 4.68 5796 24552 53452 0.88 03:06:55 PM 1832648 89916 4.68 5796 24552 53452 0.88 Average: 1832648 89916 4.68 5796 24552 53452 0.88
[7] Output the current send/receive packets for 3 times every second. [root@dlp ~]# sar -n DEV 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 03:20:05 PM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s 03:20:06 PM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 03:20:06 PM eth2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 03:20:06 PM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s 03:20:07 PM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 03:20:07 PM eth2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 03:20:07 PM IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s 03:20:08 PM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 03:20:08 PM eth2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s Average: lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: eth2 0.00 0.00 0.00 0.00 0.00 0.00 0.00
[8] Output the current paging usage for 3 times every second.
[root@dlp ~]# sar -B 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 03:13:12 PM pgpgin/s pgpgout/s fault/s majflt/s pgfree/s pgscank/s pgscand/s pgsteal/s %vmeff 03:13:13 PM 0.00 0.00 80.00 0.00 65.00 0.00 0.00 0.00 0.00 03:13:14 PM 0.00 0.00 40.00 0.00 63.00 0.00 0.00 0.00 0.00 03:13:15 PM 0.00 0.00 32.00 0.00 63.00 0.00 0.00 0.00 0.00 Average: 0.00 0.00 50.67 0.00 63.67 0.00 0.00 0.00 0.00
It’s possible to output every CPU cores’ usage with “mpstat” command like follows.
[9] Output the current all CPU cores’ usage for 3 times every second.
[root@dlp ~]# mpstat -P ALL 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 03:55:12 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle 03:55:13 PM all 0.00 0.00 0.00 0.00 0.50 0.00 0.00 0.00 99.50 03:55:13 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:13 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:13 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle 03:55:14 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:14 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:14 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:14 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle 03:55:15 PM all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:15 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:55:15 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle Average: all 0.00 0.00 0.00 0.00 0.17 0.00 0.00 0.00 99.83 Average: 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
It’s possible to output disk I/O usage with “iostat” command like follows.
[10] Output the current I/O usage with Mega-bytes for 3 times every second.
[root@dlp ~]# iostat -mx 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.01 0.00 0.03 0.08 0.00 99.87
Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util
vda 0.38 0.15 0.67 0.10 0.01 0.00 29.46 0.03 41.78 4.44 0.35
dm-0 0.00 0.00 0.76 0.25 0.01 0.00 20.34 0.06 54.84 3.25 0.33
dm-1 0.00 0.00 0.08 0.00 0.00 0.00 8.00 0.00 1.05 0.53 0.00
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.50 0.00 0.00 99.50
Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util
vda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.50 0.00 0.00 99.50
Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util
vda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
dm-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
It’s possible to output every CPU usage for processes with “pidstat” command like follows.
[11] Output the CPU usage for a process ID “1169” for 3 times every second.
[root@dlp ~]# pidstat -p 1169 1 3
Linux 2.6.32-358.6.2.el6.x86_64 (dlp.server.world) 06/25/2013 _x86_64_ (2 CPU) 04:09:09 PM PID %usr %system %guest %CPU CPU Command 04:09:10 PM 1169 0.00 0.00 0.00 0.00 1 bash 04:09:11 PM 1169 0.00 0.00 0.00 0.00 1 bash 04:09:12 PM 1169 0.00 0.00 0.00 0.00 1 bash Average: 1169 0.00 0.00 0.00 0.00 - bash