Oracle Linux - Short Tip 6 - find memory usage per process

Everyone operating a Oracle Linux machine, or any other operating system for that matter, will at a certain point have to look at memory consumption. The first question when looking at memory consumption during a memory optimization project is the question, which process is using how much memory currently. Linux provides a wide range of tools and options to gain insight in all facets of system resource usage.

For those who "just" need to have a quick insight in the current memory consumption per process on Oracle Linux the below command can be extremely handy:

ps -eo size,pid,user,command --sort -size | awk '{ hr=$1/1024 ; printf("%13.2f Mb ",hr) } { for ( x=4 ; x<=NF ; x++ ) { printf("%s ",$x) } print "" }'

It will provide a quick overview of the current memory consumption in mb per process.

[root@devopsdemo ~]# ps -eo size,pid,user,command --sort -size | awk '{ hr=$1/1024 ; printf("%13.2f Mb ",hr) } { for ( x=4 ; x<=NF ; x++ ) { printf("%s ",$x) } print "" }'
         0.00 Mb COMMAND
       524.63 Mb /usr/sbin/console-kit-daemon --no-daemon
       337.95 Mb automount --pid-file /var/run/autofs.pid
       216.54 Mb /sbin/rsyslogd -i /var/run/syslogd.pid -c 5
         8.81 Mb hald
         8.46 Mb dbus-daemon --system
         8.36 Mb auditd
         2.14 Mb /sbin/udevd -d
         2.14 Mb /sbin/udevd -d
         1.38 Mb crond
         1.11 Mb /sbin/udevd -d
         1.04 Mb ps -eo size,pid,user,command --sort -size
         0.83 Mb sshd: root@pts/0
         0.74 Mb cupsd -C /etc/cups/cupsd.conf
         0.73 Mb qmgr -l -t fifo -u
         0.73 Mb login -- root
         0.65 Mb /usr/sbin/abrtd

The overview is extremely usefull when you need to quickly find the processes that consume the most memory or memory consuming processes which are not expected to use (this much) memory.