Linux find out what process are eating all memory and time allocated to process

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Q. How do I find out what process are eating up all my memory. Is it possible to find out how long that memory has been allocated to particular process? How do I kill that process to free up memory?

A. You need to use the top command which provides a dynamic real-time view of a running system. It can display system summary information as well as a list of tasks currently being managed by the Linux kernel.

Simply type top command:
# top

top command will tell you the percentage of physical memory a particular process is using at any given time. As far as I know, there is no easy way that can tell how long that memory has been allocated.

You can also use ps command to get more information about process.
# ps aux | less

To kill process use kill command under Linux. Read man page of top and ls for more information.

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

7 comment

  2. I recommend using `htop’ instead of top to monitor processes. It’s much friendlier and easy to use, and allows you to do more. (It’s colorized too!)

    It’s in the ubuntu repositories, I imagine you can install it easily for debian as well.

  3. I prefer using atop.. which gives all the option network activity, disk activity and many more you can check in the man page of it

    I dont know abt redhat and fedora but its there in ubuntu and debian repo

  5. what about this command:

    ps axu | awk '{print $2, $3, $4, $11}' | head -1 && ps axu | awk '{print $2, $3, $4, $11}' | sort -k3 -nr |head -5

    The result is here

    PID %CPU %MEM COMMAND
2222 3.2 3.8 /usr/lib/firefox/firefox
1937 0.2 1.5 /home/sorin/.dropbox-dist/dropbox
1073 3.8 1.0 /usr/bin/X
2407 0.2 0.9 pidgin
4105 1.5 0.8 /usr/lib/firefox/plugin-container

    I see the 5 processes which consume most of the memory.
    If I want to see the CPU, then I sort after second column => sort -k2

    ps axu | awk '{print $2, $3, $4, $11}' | head -1 && ps axu | awk '{print $2, $3, $4, $11}' | sort -k2 -nr |head -5

    outputs:

    PID %CPU %MEM COMMAND
3448 16.9 0.2 rsync
1073 3.7 1.0 /usr/bin/X
2222 3.2 3.7 /usr/lib/firefox/firefox
830 2.5 0.5 /sbin/mount.ntfs
4105 1.4 0.6 /usr/lib/firefox/plugin-container

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