# To list every process on the system:
ps aux
# To list a process tree:
ps axjf
# To list every process owned by foouser:
ps -aufoouser
# To list every process with a user-defined format:
ps -eo pid,user,commandCheck high CPU usage process
# Display usage across each processor
root@satellite :~# mpstat -P ALL
Linux 5.15.0-124-generic (vmanalyst) 10/17/2024 _x86_64_ (8 CPU)
12:36:13 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
12:36:13 PM all 0.20 0.02 0.23 0.02 0.00 0.01 0.00 0.00 0.00 99.52
12:36:13 PM 0 0.26 0.00 0.23 0.03 0.00 0.02 0.00 0.00 0.00 99.46
12:36:13 PM 1 0.20 0.00 0.20 0.02 0.00 0.01 0.00 0.00 0.00 99.57
12:36:13 PM 2 0.10 0.00 0.18 0.03 0.00 0.01 0.00 0.00 0.00 99.69
12:36:13 PM 3 0.26 0.07 0.22 0.03 0.00 0.01 0.00 0.00 0.00 99.41
12:36:13 PM 4 0.13 0.02 0.13 0.02 0.00 0.01 0.00 0.00 0.00 99.70
12:36:13 PM 5 0.12 0.02 0.20 0.02 0.00 0.00 0.00 0.00 0.00 99.63
12:36:13 PM 6 0.28 0.00 0.32 0.02 0.00 0.01 0.00 0.00 0.00 99.38
12:36:13 PM 7 0.29 0.02 0.33 0.02 0.00 0.02 0.00 0.00 0.00 99.32
%usr - % CPU usage at the user level
%nice - % CPU usage for user processes labeled nice.
%sys - % CPU usage at the system (Linux kernel) level.
%iowait - % CPU usage idling waiting on a disk read/write.
%irq - % CPU usage handling hardware interrupts.
%soft - % CPU usage handling software interrupts.
%steal - % CPU usage being forced to wait for a hypervisor handling other virtual processors.
%guest - % CPU usage spent running a virtual processor.
%idle - % CPU usage on idle time (no processes and not waiting on a disk read/write).
root@vmanalyst:~#
root@satellite ~]# ps -eo pid,ppid,%mem,%cpu,cmd --sort=-%cpu | head
PID PPID %MEM %CPU CMD
963 1 0.2 0.2 /usr/bin/vmtoolsd
1894 2 0.0 0.2 [kworker/1:0-events]
2162 2 0.0 0.2 [kworker/1:3-events_freezable_power_]
1976 2 0.0 0.1 [kworker/1:1-events_power_efficient]
1 0 0.4 0.0 /usr/lib/systemd/systemd rhgb --switched-root --system --deserialize 31
2 0 0.0 0.0 [kthreadd]
3 2 0.0 0.0 [rcu_gp]
4 2 0.0 0.0 [rcu_par_gp]
5 2 0.0 0.0 [slub_flushwq]
[root@satellite ~]# ps -eo pid,ppid,%mem,%cpu,comm --sort=-%cpu | head
PID PPID %MEM %CPU COMMAND
963 1 0.2 0.2 vmtoolsd
1894 2 0.0 0.2 kworker/1:0-events
2162 2 0.0 0.2 kworker/1:3-pm
1976 2 0.0 0.1 kworker/1:1-events_power_efficient
1 0 0.4 0.0 systemd
2 0 0.0 0.0 kthreadd
3 2 0.0 0.0 rcu_gp
4 2 0.0 0.0 rcu_par_gp
5 2 0.0 0.0 slub_flushwq
root@satellite ~]# top -c -b | head -20
top - 12:54:27 up 1:23, 2 users, load average: 0.95, 0.46, 0.18
Tasks: 236 total, 1 running, 235 sleeping, 0 stopped, 0 zombie
%Cpu(s): 5.3 us, 5.3 sy, 0.0 ni, 86.8 id, 0.0 wa, 2.6 hi, 0.0 si, 0.0 st
MiB Mem : 3634.5 total, 2898.0 free, 556.6 used, 419.2 buff/cache
MiB Swap: 1536.0 total, 1536.0 free, 0.0 used. 3078.0 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2541 root 20 0 10652 3940 3304 R 5.9 0.1 0:00.04 top -c -b
1 root 20 0 173720 19372 10556 S 0.0 0.5 0:03.35 /usr/lib/systemd/systemd rhgb --switched-root --system --deserialize 31
2 root 20 0 0 0 0 S 0.0 0.0 0:00.05 [kthreadd]
3 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [rcu_gp]
4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [rcu_par_gp]
5 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [slub_flushwq]
6 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [netns]
8 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [kworker/0:0H-events_highpri]
10 root 0 -20 0 0 0 I 0.0 0.0 0:00.05 [kworker/0:1H-events_highpri]
11 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 [mm_percpu_wq]
13 root 20 0 0 0 0 I 0.0 0.0 0:00.00 [rcu_tasks_kthre]
14 root 20 0 0 0 0 I 0.0 0.0 0:00.00 [rcu_tasks_rude_]
15 root 20 0 0 0 0 I 0.0 0.0 0:00.00 [rcu_tasks_trace]
Monitor Disk I/O performance
#Check the I/O statistics of disks
[root@satellite ~]# iostat -d
Linux 5.14.0-284.11.1.el9_2.x86_64 (satellite) 26/10/23 _x86_64_ (2 CPU)
Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
dm-0 1.04 46.35 3.92 0.00 329034 27834 0
dm-1 0.01 0.33 0.00 0.00 2348 0 0
nvme0n1 1.15 55.33 4.21 0.00 392827 29920 0
nvme0n2 0.01 0.24 0.00 0.00 1712 0 0
nvme0n3 0.01 0.13 0.00 0.00 944 0 0
nvme0n4 0.01 0.13 0.00 0.00 944 0 0
nvme0n5 0.01 0.13 0.00 0.00 944 0 0
#Check the I/O statistics of all the disks and the partitions
-m = MB; - k = KB
root@satellite ~]# iostat -m
Linux 5.14.0-284.11.1.el9_2.x86_64 (satellite) 26/10/23 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.19 0.02 1.33 0.02 0.00 98.44
Device tps MB_read/s MB_wrtn/s MB_dscd/s MB_read MB_wrtn MB_dscd
dm-0 1.00 0.04 0.00 0.00 321 27 0
dm-1 0.01 0.00 0.00 0.00 2 0 0
nvme0n1 1.11 0.05 0.00 0.00 383 29 0
nvme0n2 0.01 0.00 0.00 0.00 1 0 0
nvme0n3 0.01 0.00 0.00 0.00 0 0 0
nvme0n4 0.01 0.00 0.00 0.00 0 0 0
nvme0n5 0.01 0.00 0.00 0.00 0 0 0
#Check the disk wait times
[root@satellite ~]# iostat -x
Linux 5.14.0-284.11.1.el9_2.x86_64 (satellite) 26/10/23 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.18 0.02 1.33 0.02 0.00 98.44
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz w/s wkB/s wrqm/s %wrqm w_await wareq-sz d/s dkB/s drqm/s %drqm d_await dareq-sz f/s f_await aqu-sz %util
dm-0 0.79 44.05 0.00 0.00 0.67 55.68 0.20 3.74 0.00 0.00 4.31 18.39 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.09
dm-1 0.01 0.31 0.00 0.00 0.29 23.72 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nvme0n1 0.91 52.59 0.16 15.22 0.73 57.92 0.19 4.02 0.02 7.79 3.63 21.14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10
nvme0n2 0.01 0.23 0.00 0.00 0.29 25.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nvme0n3 0.01 0.13 0.00 0.00 0.34 15.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nvme0n4 0.01 0.13 0.00 0.00 0.27 15.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nvme0n5 0.01 0.13 0.00 0.00 0.29 15.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Check high Memory usage process
root@vmanalyst:~# top -b | head -10
top - 12:44:05 up 2:17, 2 users, load average: 0.00, 0.00, 0.00
Tasks: 341 total, 1 running, 340 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.2 us, 1.2 sy, 0.0 ni, 97.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 3875.9 total, 2128.3 free, 746.4 used, 1001.2 buff/cache
MiB Swap: 3891.0 total, 3891.0 free, 0.0 used. 2857.6 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3511 root 20 0 10612 4256 3388 R 11.1 0.1 0:00.06 top
1446 gdm 20 0 3929112 186220 112244 S 5.6 4.7 0:30.39 gnome-shell
1 root 20 0 168400 13856 8416 S 0.0 0.3 0:22.28 systemd
root@vmanalyst:~# free -m
total used free shared buff/cache available
Mem: 3875 746 2128 16 1001 2857
Swap: 3890 0 3890
root@vmanalyst:~#
root@vmanalyst:~# cat /proc/meminfo
MemTotal: 3968920 kB
MemFree: 2179644 kB
MemAvailable: 2926440 kB
Buffers: 48184 kB
Cached: 879668 kB
SwapCached: 0 kB
Active: 196820 kB
root@vmanalyst:~# vmstat -s -S M
3875 M total memory
734 M used memory
191 M active memory
1073 M inactive memory
2139 M free memory
46 M buffer memory
954 M swap cache
3890 M total swap
0 M used swap
3890 M free swap
12568 non-nice user cpu ticks
1119 nice user cpu ticks
13959 system cpu ticks
6031143 idle cpu ticks
1277 IO-wait cpu ticks
0 IRQ cpu ticks
733 softirq cpu ticks
0 stolen cpu ticks
800480 pages paged in
347824 pages paged out
0 pages swapped in
0 pages swapped out
1029663 interrupts
1243021 CPU context switches
1729160804 boot time
3565 forks
root@vmanalyst:~#Using Top Command
System hides all idle process, making it easier to view
root@vmanalyst:~# top -i
top - 12:26:08 up 1:59, 2 users, load average: 0.01, 0.02, 0.00
Tasks: 336 total, 1 running, 335 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.2 us, 0.1 sy, 0.0 ni, 99.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 3875.9 total, 2556.9 free, 752.9 used, 566.1 buff/cache
MiB Swap: 3891.0 total, 3891.0 free, 0.0 used. 2868.2 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1981 root 20 0 10740 4364 3408 R 1.0 0.1 0:51.63 top
937 root 20 0 314804 9360 7700 S 0.3 0.2 0:29.07 vmtoolsd
1446 gdm 20 0 3929112 186220 112244 S 0.3 4.7 0:27.38 gnome-shell
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