Tips to find process utilization in a Linux machine

The ps command has several flags that enable you to specify which processes to list and what information to display about each process.

To show all processes running on your system, at the prompt, type the following:

ps -ef

The system displays information similar to the following:

    USER   PID  PPID   C    STIME    TTY  TIME CMD
    root     1     0   0   Jun 28      -  3:23 /etc/init 
    root  1588  6963   0   Jun 28      -  0:02 /usr/etc/biod 6 
    root  2280     1   0   Jun 28      -  1:39 /etc/syncd 60 
    mary  2413 16998   2 07:57:30      -  0:05 aixterm 
    mary 11632 16998   0 07:57:31  lft/1  0:01 xbiff 
    mary 16260  2413   1 07:57:35  pts/1  0:00 /bin/ksh 
    mary 16469     1   0 07:57:12  lft/1  0:00 ksh /usr/lpp/X11/bin/xinit 
    mary 19402 16260  20 09:37:21  pts/1  0:00 ps -ef 

The columns in the previous output are defined as follows:

Item Description

---------------

USER User login name

PID         Process ID

PPID Parent process ID

C         CPU utilization of process

STIME Start time of process

TTY         Controlling workstation for the process

TIME Total execution time for the process

CMD Command

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In the previous example, the process ID for the ps -ef command is 19402. Its parent process ID is 16260, the /bin/kshcommand.

If the listing is very long, the top portion scrolls off the screen. To display the listing one page (screen) at a time, pipe the pscommand to the pg command. At the prompt, type the following:

ps -ef | pg

To display status information of all processes running on your system, at the prompt, type the following:

ps gv

This form of the command lists a number of statistics for each active process. Output from this command looks similar to the following:

   PID    TTY STAT  TIME PGIN  SIZE   RSS   LIM  TSIZ   TRS %CPU %MEM COMMAND
     0      - A     0:44    7     8     8    xx     0     0  0.0  0.0 swapper
     1      - A     1:29  518   244   140    xx    21    24  0.1  1.0 /etc/init
   771      - A     1:22    0    16    16    xx     0     0  0.0  0.0 kproc
  1028      - A     0:00   10    16     8    xx     0     0  0.0  0.0 kproc
  1503      - A     0:33  127    16     8    xx     0     0  0.0  0.0 kproc
  1679      - A     1:03  282   192    12 32768   130     0  0.7  0.0 pcidossvr
  2089      - A     0:22  918    72    28    xx     1     4  0.0  0.0 /etc/sync
  2784      - A     0:00    9    16     8    xx     0     0  0.0  0.0 kproc
  2816      - A     5:59 6436  2664   616     8   852   156  0.4  4.0 /usr/lpp/
  3115      - A     0:27  955   264   128    xx    39    36  0.0  1.0 /usr/lib/
  3451      - A     0:00    0    16     8    xx     0     0  0.0  0.0 kproc
  3812      - A     0:00   21   128    12 32768    34     0  0.0  0.0 usr/lib/lpd/
  3970      - A     0:00    0    16     8    xx     0     0  0.0  0.0 kproc
  4267      - A     0:01  169   132    72 32768    16    16  0.0  0.0 /etc/sysl
  4514  lft/0 A     0:00   60   200    72    xx    39    60  0.0  0.0 /etc/gett
  4776  pts/3 A     0:02  250   108   280     8   303   268  0.0  2.0 -ksh 
  5050      - A     0:09 1200   424   132 32768   243    56  0.0  1.0 /usr/sbin
  5322      - A     0:27 1299   156   192    xx    24    24  0.0  1.0 /etc/cron
  5590      - A     0:00    2   100    12 32768    11     0  0.0  0.0 /etc/writ
  5749      - A     0:00    0   208    12    xx    13     0  0.0  0.0 /usr/lpp/
  6111      - T     0:00   66   108    12 32768    47     0  0.0  0.0 /usr/lpp/