Ceci est une ancienne révision du document !
Table des matières
Version : 2022.01
Updated: 2022/10/03 04:54
Topic 1 - Capacity Planning
Contents
- Topic 1 - Capacity Planning
- Contents
- LAB #1 - Measuring System Resource Usage
- 1.1 - free
- 1.2 - uptime ou w
- 1.3 - iostat
- 1.4 - hdparm
- 1.5 - vmstat
- 1.6 - mpstat
- 1.7 - sar
- LAB #2 - Viewing Open Files and Running Processes
- Presentation
- Process Types
- Process Commands
- The ps Command
- The pstree Command
- The top Command
LAB#1 - Interpreting Information in /proc
The information found in files in the /proc filesystem can be interpreted using the following commands:
- free,
- uptime et w,
- iostat,
- hdparm
- vmstat,
- mpstat,
- sar.
1.1 - The free Command
The free command shows total, used, free, shared, buffered, cached and swapped memory:
[root@centos8 ~]# free -m
total used free shared buff/cache available
Mem: 3735 1135 1818 14 782 2363
Swap: 3279 0 3279
In the above example, you can see:
- 3735 MB of total physical memory,
- 1135 MB of used physical memory and 1818 MB of free physical memory,
- 3279 MB of swap space with 0MB being used.
The command line switches of this command are:
[root@centos8 ~]# free --help
Usage:
free [options]
Options:
-b, --bytes show output in bytes
--kilo show output in kilobytes
--mega show output in megabytes
--giga show output in gigabytes
--tera show output in terabytes
--peta show output in petabytes
-k, --kibi show output in kibibytes
-m, --mebi show output in mebibytes
-g, --gibi show output in gibibytes
--tebi show output in tebibytes
--pebi show output in pebibytes
-h, --human show human-readable output
--si use powers of 1000 not 1024
-l, --lohi show detailed low and high memory statistics
-t, --total show total for RAM + swap
-s N, --seconds N repeat printing every N seconds
-c N, --count N repeat printing N times, then exit
-w, --wide wide output
--help display this help and exit
-V, --version output version information and exit
For more details see free(1).
1.2 - The uptime and w Commands
Each of these commands show the load average over the past 1, 5 and 15 minutes:
[root@centos8 ~]# uptime 04:39:03 up 1 day, 2:34, 1 user, load average: 0.00, 0.00, 0.00 [root@centos8 ~]# w 04:39:04 up 1 day, 2:34, 1 user, load average: 0.00, 0.00, 0.00 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT trainee pts/0 10.0.2.1 03:58 0.00s 0.11s 0.02s sshd: trainee [priv]
The load average indicates the number of processes being executed and waiting to be executed for the period concerned.
If the load average of a single-core system was 3.48 4.00 3.85 this would indicate a bottleneck since, on average:
- 2.48 processes would have been waiting to be executed over the last minute,
- 3.00 processes would have been waiting to be executed over the last 5 minutes,
- 2.85 processes would have been waiting to be executed over the last 15 minutes,
The command line switches of these commands are:
[root@centos8 ~]# uptime --help
Usage:
uptime [options]
Options:
-p, --pretty show uptime in pretty format
-h, --help display this help and exit
-s, --since system up since
-V, --version output version information and exit
For more details see uptime(1).
[root@centos8 ~]# w --help
Usage:
w [options]
Options:
-h, --no-header do not print header
-u, --no-current ignore current process username
-s, --short short format
-f, --from show remote hostname field
-o, --old-style old style output
-i, --ip-addr display IP address instead of hostname (if possible)
--help display this help and exit
-V, --version output version information and exit
For more details see w(1).
1.3 - The iostat Command
The iostat command show disk, terminal and streamer statistics:
[root@centos8 ~]# iostat
bash: iostat: command not found...
Install package 'sysstat' to provide command 'iostat'? [N/y] y
* Waiting in queue...
The following packages have to be installed:
lm_sensors-libs-3.4.0-22.20180522git70f7e08.el8.x86_64 Lm_sensors core libraries
sysstat-11.7.3-5.el8.x86_64 Collection of performance monitoring tools for Linux
Proceed with changes? [N/y] y
* Waiting in queue...
* Waiting for authentication...
* Waiting in queue...
* Downloading packages...
* Requesting data...
* Testing changes...
* Installing packages...
Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_(8 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.03 0.00 0.03 0.01 0.00 99.93
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 0.28 7.67 1.49 735338 142510
sdb 0.00 0.03 0.00 2995 0
scd0 0.00 0.00 0.00 2 0
dm-0 0.26 7.25 1.55 694786 148837
dm-1 0.00 0.02 0.00 2220 0
[root@centos8 ~]# iostat -d -x Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 30/06/21 _x86_64_ (8 CPU) Device r/s w/s rkB/s wkB/s rrqm/s wrqm/s %rrqm %wrqm r_await w_await aqu-sz rareq-sz wareq-sz svctm %util sda 0.20 0.16 11.67 1.81 0.00 0.03 0.48 17.45 6.79 69.99 0.01 58.28 11.33 9.13 0.33 sdb 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.13 0.00 0.00 8.81 0.00 0.51 0.00 scd0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.20 0.00 0.00 0.20 0.00 0.90 0.00 dm-0 0.12 0.19 3.98 1.90 0.00 0.00 0.00 0.00 4.18 79.07 0.02 32.88 10.07 10.34 0.32 dm-1 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.76 0.00 0.00 21.35 0.00 0.68 0.00
The command line switches of this command are:
[root@centos8 ~]# iostat --help
Usage: iostat [ options ] [ <interval> [ <count> ] ]
Options are:
[ -c ] [ -d ] [ -h ] [ -k | -m ] [ -N ] [ -s ] [ -t ] [ -V ] [ -x ] [ -y ] [ -z ]
[ -j { ID | LABEL | PATH | UUID | ... } ] [ --human ] [ -o JSON ]
[ [ -H ] -g <group_name> ] [ -p [ <device> [,...] | ALL ] ]
[ <device> [...] | ALL ]
1.4 - The hdparm Command
The hdparm command measures disk reads:
[root@centos8 ~]# hdparm -t /dev/sda /dev/sda: Timing buffered disk reads: 1410 MB in 3.00 seconds = 469.98 MB/sec
1.5 - La Commande vmstat
The vmstat commands shows memory, pagination and processor statistics:
[root@centos8 ~]# vmstat 1 10 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 1765216 2256 866336 0 0 3 0 9 12 0 0 100 0 0 0 0 0 1765136 2256 866336 0 0 0 0 57 80 0 0 100 0 0 0 0 0 1765136 2256 866376 0 0 0 0 54 77 0 0 100 0 0 0 0 0 1765136 2256 866376 0 0 0 0 66 100 0 0 100 0 0 0 0 0 1765136 2256 866376 0 0 0 0 103 125 0 0 100 0 0 0 0 0 1765108 2256 866376 0 0 0 0 64 86 0 0 100 0 0 0 0 0 1765108 2256 866376 0 0 0 0 62 88 0 0 100 0 0 0 0 0 1765108 2256 866376 0 0 0 0 68 97 0 0 100 0 0 0 0 0 1765108 2256 866376 0 0 0 0 60 88 0 0 100 0 0 0 0 0 1765108 2256 866376 0 0 0 0 177 251 0 0 100 0 0
The command line switches of this command are:
[root@centos8 ~]# vmstat --help Usage: vmstat [options] [delay [count]] Options: -a, --active active/inactive memory -f, --forks number of forks since boot -m, --slabs slabinfo -n, --one-header do not redisplay header -s, --stats event counter statistics -d, --disk disk statistics -D, --disk-sum summarize disk statistics -p, --partition <dev> partition specific statistics -S, --unit <char> define display unit -w, --wide wide output -t, --timestamp show timestamp -h, --help display this help and exit -V, --version output version information and exit For more details see vmstat(8).
Important : By default vmstat shows statistics from boot until current time.
1.6 - The mpstat Command
La commande mpstat affiche des statistiques détaillées sur le CPU :
[root@centos8 ~]# mpstat Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_(8 CPU) 04:53:22 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:53:22 all 0.03 0.00 0.01 0.02 0.01 0.01 0.00 0.00 0.00 99.92
If there are several CPU's in the system, statistics can be viewed by core and as an average:
[root@centos8 ~]# mpstat -P ALL Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_(8 CPU) 04:54:28 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:54:28 all 0.03 0.00 0.01 0.02 0.01 0.01 0.00 0.00 0.00 99.92 04:54:28 0 0.03 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 99.94 04:54:28 1 0.02 0.00 0.02 0.03 0.02 0.00 0.00 0.00 0.00 99.91 04:54:28 2 0.02 0.00 0.01 0.01 0.01 0.04 0.00 0.00 0.00 99.90 04:54:28 3 0.01 0.00 0.01 0.02 0.00 0.00 0.00 0.00 0.00 99.95 04:54:28 4 0.05 0.00 0.02 0.03 0.01 0.00 0.00 0.00 0.00 99.88 04:54:28 5 0.03 0.01 0.01 0.02 0.01 0.00 0.00 0.00 0.00 99.92 04:54:28 6 0.02 0.00 0.02 0.01 0.01 0.00 0.00 0.00 0.00 99.95 04:54:28 7 0.02 0.00 0.01 0.01 0.01 0.00 0.00 0.00 0.00 99.94
Finally, mpstat is capable of showing statistics over time. In the following example you can see 5 data sets, one taken every 2 seconds:
[root@centos8 ~]# mpstat -P ALL 2 5 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 04:55:11 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:55:13 all 0.00 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.00 99.94 04:55:13 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 4 0.00 0.00 0.00 0.00 0.00 0.00 0.50 0.00 0.00 99.50 04:55:13 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:13 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:55:15 all 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 99.94 04:55:15 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:15 7 0.00 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.00 99.50 04:55:15 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:55:17 all 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 99.94 04:55:17 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 2 0.00 0.00 0.00 0.00 0.50 0.00 0.00 0.00 0.00 99.50 04:55:17 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:17 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:55:19 all 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:19 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 04:55:21 all 0.06 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.94 04:55:21 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 04:55:21 7 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.50 Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 0.01 0.00 0.00 0.00 0.02 0.00 0.01 0.00 0.00 99.95 Average: 0 0.00 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 0.00 100.00 Average: 2 0.00 0.00 0.00 0.00 0.10 0.00 0.00 0.00 0.00 99.90 Average: 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: 4 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.00 0.00 99.90 Average: 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: 7 0.10 0.00 0.00 0.00 0.10 0.00 0.00 0.00 0.00 99.80
The command line switches of this command are:
[root@centos8 ~]# mpstat --help
Usage: mpstat [ options ] [ <interval> [ <count> ] ]
Options are:
[ -A ] [ -n ] [ -u ] [ -V ] [ -I { SUM | CPU | SCPU | ALL } ]
[ -N { <node_list> | ALL } ] [ -o JSON ] [ -P { <cpu_list> | ALL } ]
1.7 - The sar Command
The sar command can survey all system resources dependant upon the switch that is used. Several important switches are:
| Switch | Description |
|---|---|
| -u | CPU usage in % |
| -q | Number of processes in the process queue |
| -r | Memory usage |
| -w | Swap usage |
| -p | Pagination usage |
| -b | Buffer usage |
| -d | Disk usage |
The /usr/lib64/sa/sadc command is used to collect data:
[root@centos8 ~]# ls /usr/lib64/sa sa1 sa2 sadc
The /usr/lib64/sa/sa1 script calls the /usr/lib/sa/sadc command and can use two switches:
| Switch | Description |
|---|---|
| -t | Interval |
| -n | Count |
The /usr/lib64/sa/sa2 script also creates a log at /var/log/sa/sar<dd>, where <dd> is the day of the month.
[root@centos8 ~]# ls /var/log/sa/ sa29 s ar29
Using CentOS / RHEL 8, the interval between collects is configured using systemd timers de systemd and not cron as was previously the case:
[root@centos8 ~]# cat /usr/lib/systemd/system/sysstat-collect.timer # /usr/lib/systemd/system/sysstat-collect.timer # (C) 2014 Tomasz Torcz <tomek@pipebreaker.pl> # # sysstat-11.7.3 systemd unit file: # Activates activity collector every 10 minutes [Unit] Description=Run system activity accounting tool every 10 minutes [Timer] OnCalendar=*:00/10 [Install] WantedBy=sysstat.service
The OnCalendar value indicates a collect every 10 minutes.
To change this value, you need to create an override file in /etc/systemd/system/ by using the systemctl edit command. You should never edit directly files in /usr/lib/systemd/system :
[root@centos8 ~]# systemctl edit sysstat-collect.timer [root@centos8 ~]# cat /etc/systemd/system/sysstat-collect.timer.d/override.conf [Unit] Description=Run system activity accounting tool every 2 minutes [Timer] OnCalendar= OnCalendar=*:00/2 AccuracySec=0
Important : Note the line OnCalendar= which is required to override the default value.
Now check if the configuration has been applied:
[root@centos8 ~]# systemctl status sysstat-collect.timer
● sysstat-collect.timer - Run system activity accounting tool every 2 minutes
Loaded: loaded (/usr/lib/systemd/system/sysstat-collect.timer; enabled; vendor preset: disabled)
Drop-In: /etc/systemd/system/sysstat-collect.timer.d
└─override.conf
Active: active (waiting) since Tue 2021-06-29 06:16:04 EDT; 3h 2min ago
Trigger: Tue 2021-06-29 09:20:00 EDT; 1min 19s left
Jun 29 06:16:04 centos8.ittraining.loc systemd[1]: Started Run system activity accounting tool every 10 minutes.
[root@centos8 ~]# journalctl -g sysstat-collect.service -- Logs begin at Mon 2021-06-28 02:04:10 EDT, end at Tue 2021-06-29 09:18:00 EDT. -- Jun 29 06:20:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 06:26:29 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 06:30:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 06:40:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 06:50:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:00:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:10:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:20:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:30:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:40:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:50:33 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:53:56 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:54:00 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:56:00 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 07:58:00 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. Jun 29 08:00:00 centos8.ittraining.loc systemd[1]: sysstat-collect.service: Succeeded. ...
Execute the sar command:
[root@centos8 ~]# sar Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 06:16:04 LINUX RESTART (8 CPU) 06:20:33 CPU %user %nice %system %iowait %steal %idle 06:26:29 all 0.03 0.00 0.03 0.00 0.00 99.94 06:30:33 all 0.02 0.00 0.03 0.00 0.00 99.95 06:40:33 all 0.02 0.00 0.03 0.00 0.00 99.94 06:50:33 all 0.02 0.00 0.02 0.00 0.00 99.95 07:00:33 all 0.02 0.00 0.02 0.00 0.00 99.95 07:10:33 all 0.02 0.00 0.02 0.00 0.00 99.95 07:20:33 all 0.02 0.00 0.03 0.00 0.00 99.95 07:30:33 all 0.02 0.01 0.03 0.00 0.00 99.94 07:40:33 all 0.03 0.00 0.04 0.00 0.00 99.93 07:50:33 all 0.03 0.00 0.03 0.00 0.00 99.94 07:53:56 all 0.08 0.00 0.06 0.00 0.00 99.86 07:54:00 all 0.09 0.00 0.06 0.00 0.00 99.85 Average: all 0.03 0.00 0.03 0.00 0.00 99.94 07:55:44 LINUX RESTART (8 CPU) 07:56:00 CPU %user %nice %system %iowait %steal %idle 07:58:00 all 0.03 0.00 0.03 0.00 0.00 99.94 08:00:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:02:00 all 0.02 0.00 0.03 0.00 0.00 99.94 08:04:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:06:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:08:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:10:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:12:00 all 0.03 0.00 0.03 0.00 0.00 99.95 08:14:00 all 0.02 0.00 0.03 0.01 0.00 99.94 08:16:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:18:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:20:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:22:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:24:00 all 0.02 0.00 0.02 0.00 0.00 99.95 08:26:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:28:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:30:00 all 0.02 0.05 0.05 0.00 0.00 99.87 08:32:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:34:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:36:00 all 0.03 0.00 0.04 0.00 0.00 99.94 08:38:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:40:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:42:00 all 0.02 0.00 0.03 0.00 0.00 99.94 08:44:00 all 0.03 0.00 0.03 0.00 0.00 99.94 08:46:00 all 0.02 0.00 0.03 0.00 0.00 99.94 08:48:00 all 0.03 0.00 0.03 0.00 0.00 99.95 08:50:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:52:00 all 0.02 0.00 0.06 0.00 0.00 99.92 08:54:00 all 0.02 0.00 0.03 0.00 0.00 99.95 08:56:00 all 0.02 0.00 0.04 0.00 0.00 99.94 08:58:00 all 0.02 0.00 0.02 0.00 0.00 99.96 09:00:00 all 0.07 0.00 0.05 0.00 0.00 99.88 09:02:00 all 0.02 0.00 0.04 0.00 0.00 99.94 09:04:00 all 0.02 0.00 0.03 0.00 0.00 99.95 09:06:00 all 0.02 0.00 0.04 0.00 0.00 99.94 09:08:00 all 0.02 0.00 0.04 0.00 0.00 99.94 09:10:00 all 0.02 0.00 0.03 0.00 0.00 99.95 09:12:00 all 0.02 0.00 0.03 0.00 0.00 99.94 09:12:00 CPU %user %nice %system %iowait %steal %idle 09:14:00 all 0.02 0.00 0.03 0.00 0.00 99.95 09:16:00 all 0.02 0.00 0.06 0.00 0.00 99.92 09:18:00 all 0.03 0.00 0.03 0.00 0.00 99.95 09:20:00 all 0.02 0.00 0.03 0.00 0.00 99.94 Average: all 0.02 0.00 0.03 0.00 0.00 99.94
CPU Stats
Use the -u switch:
[root@centos8 ~]# sar -u 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 09:22:52 CPU %user %nice %system %iowait %steal %idle 09:22:57 all 0.03 0.00 0.03 0.00 0.00 99.95 09:23:02 all 0.03 0.00 0.03 0.00 0.00 99.95 09:23:07 all 0.00 0.00 0.03 0.00 0.00 99.97 Average: all 0.02 0.00 0.03 0.00 0.00 99.96
More information can be shown by using the ALL argument:
[root@centos8 ~]# sar -u ALL 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_(8 CPU) 01:49:14 CPU %usr %nice %sys %iowait %steal %irq %soft %guest %gnice %idle 01:49:19 all 0.03 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 99.95 01:49:24 all 0.03 0.00 0.03 0.00 0.00 0.10 0.05 0.00 0.00 99.80 01:49:29 all 0.00 0.00 0.00 0.25 0.00 0.10 0.05 0.00 0.00 99.60 Average: all 0.02 0.00 0.01 0.08 0.00 0.08 0.03 0.00 0.00 99.78
To see the statistics from a specific core, use the -P switch:
[root@centos8 ~]# sar -u -P 1 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 01:51:52 CPU %user %nice %system %iowait %steal %idle 01:51:57 1 0.00 0.00 0.00 0.00 0.00 100.00 01:52:02 1 0.20 0.00 0.00 0.00 0.00 99.80 01:52:07 1 0.00 0.00 0.00 0.00 0.00 100.00 Average: 1 0.07 0.00 0.00 0.00 0.00 99.93 [root@centos8 ~]# sar -u -P 5 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 01:52:16 CPU %user %nice %system %iowait %steal %idle 01:52:21 5 0.00 0.00 0.00 0.00 0.00 100.00 01:52:26 5 0.00 0.00 0.00 0.00 0.00 100.00 01:52:31 5 0.00 0.00 0.00 0.00 0.00 100.00 Average: 5 0.00 0.00 0.00 0.00 0.00 100.00
Memory and Swap Statistics
Use the -r switch to see memory statistics:
[root@centos8 ~]# sar -r 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 30/06/21 _x86_64_(8 CPU) 07:33:32 kbmemfree kbavail kbmemused %memused kbbuffers kbcached kbcommit %commit kbactive kbinact kbdirty 07:33:37 1647240 2297232 2177792 56.94 3356 827396 5096432 70.94 359072 1486368 0 07:33:42 1647232 2297224 2177800 56.94 3356 827396 5095788 70.93 359072 1486300 0 07:33:47 1647232 2297224 2177800 56.94 3356 827396 5095788 70.93 359072 1486376 0 Average: 1647235 2297227 2177797 56.94 3356 827396 5096003 70.94 359072 1486348 0
Use the -S switch to see swap statistics:
[root@centos8 ~]# sar -S 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 30/06/21 _x86_64_(8 CPU) 07:31:58 kbswpfree kbswpused %swpused kbswpcad %swpcad 07:32:03 3358716 0 0.00 0 0.00 07:32:08 3358716 0 0.00 0 0.00 07:32:13 3358716 0 0.00 0 0.00 Average: 3358716 0 0.00 0 0.00
I/O Statistics
Use the -b switch:
[root@centos8 ~]# sar -b 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 09:24:49 tps rtps wtps bread/s bwrtn/s 09:24:54 0.00 0.00 0.00 0.00 0.00 09:24:59 1.20 0.00 1.20 0.00 20.20 09:25:04 0.00 0.00 0.00 0.00 0.00 Average: 0.40 0.00 0.40 0.00 6.73
Disk I/O Statistics
Use the -d switch:
[root@centos8 ~]# sar -d 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 29/06/21 _x86_64_ (8 CPU) 09:25:45 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 09:25:50 dev8-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:50 dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:50 dev11-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:50 dev253-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:50 dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:50 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 09:25:55 dev8-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:55 dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:55 dev11-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:55 dev253-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:55 dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:25:55 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 09:26:00 dev8-0 0.60 0.00 0.30 0.50 0.01 13.00 13.00 0.78 09:26:00 dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:26:00 dev11-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 09:26:00 dev253-0 0.60 0.00 0.50 0.83 0.01 12.67 13.00 0.78 09:26:00 dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util Average: dev8-0 0.20 0.00 0.10 0.50 0.00 13.00 13.00 0.26 Average: dev8-16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: dev11-0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: dev253-0 0.20 0.00 0.17 0.83 0.00 12.67 13.00 0.26 Average: dev253-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
The DEV column identifies the disks by their major/minor numbers. To see the names of the disks add the, -p switch:
[root@centos8 ~]# sar -p -d 5 3 Linux 4.18.0-305.3.1.el8.x86_64 (centos8.ittraining.loc) 30/06/21 _x86_64_ (8 CPU) 07:48:32 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 07:48:37 sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:37 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:37 sr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:37 cl_centos8-root 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:37 cl_centos8-swap 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:37 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 07:48:42 sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:42 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:42 sr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:42 cl_centos8-root 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:42 cl_centos8-swap 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:42 DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util 07:48:47 sda 0.40 0.00 0.40 1.00 0.02 56.00 56.50 2.26 07:48:47 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:47 sr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 07:48:47 cl_centos8-root 0.40 0.00 0.80 2.00 0.02 56.00 56.50 2.26 07:48:47 cl_centos8-swap 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: DEV tps rkB/s wkB/s areq-sz aqu-sz await svctm %util Average: sda 0.13 0.00 0.13 1.00 0.01 56.00 56.50 0.75 Average: sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: sr0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: cl_centos8-root 0.13 0.00 0.27 2.00 0.01 56.00 56.50 0.75 Average: cl_centos8-swap 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
The command line switches of this command are:
[root@centos8 ~]# sar --help
Usage: sar [ options ] [ <interval> [ <count> ] ]
Main options and reports (report name between square brackets):
-B Paging statistics [A_PAGE]
-b I/O and transfer rate statistics [A_IO]
-d Block devices statistics [A_DISK]
-F [ MOUNT ]
Filesystems statistics [A_FS]
-H Hugepages utilization statistics [A_HUGE]
-I { <int_list> | SUM | ALL }
Interrupts statistics [A_IRQ]
-m { <keyword> [,...] | ALL }
Power management statistics [A_PWR_...]
Keywords are:
CPU CPU instantaneous clock frequency
FAN Fans speed
FREQ CPU average clock frequency
IN Voltage inputs
TEMP Devices temperature
USB USB devices plugged into the system
-n { <keyword> [,...] | ALL }
Network statistics [A_NET_...]
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)
FC Fibre channel HBAs
SOFT Software-based network processing
-q Queue length and load average statistics [A_QUEUE]
-r [ ALL ]
Memory utilization statistics [A_MEMORY]
-S Swap space utilization statistics [A_MEMORY]
-u [ ALL ]
CPU utilization statistics [A_CPU]
-v Kernel tables statistics [A_KTABLES]
-W Swapping statistics [A_SWAP]
-w Task creation and system switching statistics [A_PCSW]
-y TTY devices statistics [A_SERIAL]
