Monitoring Swap Usage for Each Process With the top Command

To monitor which process is using swap, you can use the top command:
Log in to Advanced shell (bash).
Type the following command to enter the top utility:

# top

[root@unixonline]# top
top - 01:10:24 up 230 days,  9:05,  9 users,  load average: 0.00, 0.01, 0.05
Tasks: 220 total,   1 running, 219 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.1 us,  0.1 sy,  0.0 ni, 99.8 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  8173900 total,   208380 free,  1598880 used,  6366640 buff/cache
KiB Swap:        0 total,        0 free,        0 used.  5833596 avail Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
24275 dirsrv    20   0 1081116 170152  44012 S   0.3  2.1   1198:56 ns-slapd
31097 root      20   0  162104   2352   1592 R   0.3  0.0   0:00.02 top
    1 root      20   0  191372   4416   2616 S   0.0  0.1  80:15.97 systemd
    2 root      20   0       0      0      0 S   0.0  0.0   0:15.50 kthreadd
    4 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/0:+
    6 root      20   0       0      0      0 S   0.0  0.0   2:34.12 ksoftirqd/0
    7 root      rt   0       0      0      0 S   0.0  0.0   0:52.99 migration/0
    8 root      20   0       0      0      0 S   0.0  0.0   0:00.00 rcu_bh
    9 root      20   0       0      0      0 S   0.0  0.0  24:10.74 rcu_sched
   10 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 lru-add-dr+
   11 root      rt   0       0      0      0 S   0.0  0.0   1:33.41 watchdog/0
   12 root      rt   0       0      0      0 S   0.0  0.0   1:17.54 watchdog/1
   13 root      rt   0       0      0      0 S   0.0  0.0   0:34.23 migration/1
   14 root      20   0       0      0      0 S   0.0  0.0   2:10.22 ksoftirqd/1
   16 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/1:+
   17 root      rt   0       0      0      0 S   0.0  0.0   1:15.58 watchdog/2
   18 root      rt   0       0      0      0 S   0.0  0.0   0:28.49 migration/2

Press f to edit the columns display.
Press down to navigate down to the SWAP = Swapped Size (KiB) row.

Press right to select it for move.
Press up to move SWAP = Swapped Size (KiB) just directly above the COMMAND = Command Name/Line row.
Press Enter to commit.
Press space to add SWAP = Swapped Size (KiB) as a column to the top output. You may observe an additional * next to SWAP similar to the following example:

  • SWAP = Swapped Size (KiB)
  • COMMAND = Command Name/Line

Press Esc to exit edit mode.
Press shift+w to save the changes to the ~/.toprc file(top’s Config File). You may observe a momentary message similar to the following:
Wrote configuration to ‘/root/.toprc’

[root@unixonline]# ls -al .toprc
-rw-r--r-- 1 root root 966 Dec 18 01:12 .toprc

The next time you start top, the swap column is displayed according to the settings in .toprc file.

[root@unixonline]# top
top - 01:14:37 up 230 days,  9:10,  9 users,  load average: 0.00, 0.01, 0.05
Tasks: 219 total,   1 running, 218 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us,  2.9 sy,  0.0 ni, 97.1 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  8173900 total,   210268 free,  1596928 used,  6366704 buff/cache
KiB Swap:        0 total,        0 free,        0 used.  5835556 avail Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+   SWAP
31317 root      20   0  162104   2284   1560 R   6.2  0.0   0:00.02      0
    1 root      20   0  191372   4416   2616 S   0.0  0.1  80:16.02      0
    2 root      20   0       0      0      0 S   0.0  0.0   0:15.50      0
    4 root       0 -20       0      0      0 S   0.0  0.0   0:00.00      0
    6 root      20   0       0      0      0 S   0.0  0.0   2:34.17      0
    7 root      rt   0       0      0      0 S   0.0  0.0   0:52.99      0
    8 root      20   0       0      0      0 S   0.0  0.0   0:00.00      0
    9 root      20   0       0      0      0 S   0.0  0.0  24:10.75      0
   10 root       0 -20       0      0      0 S   0.0  0.0   0:00.00      0
   11 root      rt   0       0      0      0 S   0.0  0.0   1:33.41      0
   12 root      rt   0       0      0      0 S   0.0  0.0   1:17.54      0
   13 root      rt   0       0      0      0 S   0.0  0.0   0:34.23      0
   14 root      20   0       0      0      0 S   0.0  0.0   2:10.22      0
   16 root       0 -20       0      0      0 S   0.0  0.0   0:00.00      0
   17 root      rt   0       0      0      0 S   0.0  0.0   1:15.58      0
   18 root      rt   0       0      0      0 S   0.0  0.0   0:28.49      0
   19 root      20   0       0      0      0 S   0.0  0.0   0:21.53      0

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