Going indepth of Linux process

Scenario: 

At times need arises to dig in deep about a running process. We may be seeing a process occupying more system resource, in that case, we have to find what does that process actually doing and which are all the files it is accessing.

Solution:

There are multiple ways:

1.       Using ‘ps’ with appropriate options  (This will give show you the process tree of all process)

# ps axjf 

# ps eauxf

2.       Using ‘lsof’   (‘-p’ and ‘-c’ shows you the files opened by a particular process and command respectively)

# lsof -p  <PID>                

To know PID of a process name (e.g smbd),
# pidof  [process name]      (i.e # pidof smbd)

# lsof -c  <Command name>

Wanna go still deeper………………………………………………………………….??

3.       Use ‘strace’  ( Will list out all the System calls and Signals made by a Process. It records the System calls “C functions” which are called by a  process  and  the  Signals  which  are received by a process)

#  strace -f -p  <PID>


Use 'pidstat' to find out processes wise memory consumption. To find Memory usage of active process :

# pidstat -l -r | sort -k8nr