How can I find the processes which use the most memory? [duplicate]

Question

Possible Duplicate:
How can I display the memory usage of each process if i do a 'ps -ef'

For example, how can I find the top 20 processes that occupy the most memory?

My Linux system is going to run out of memory...

How can I find the processes which I can kill, in order to have enough memory to keep my Linux safely up and running?

[mirror@home tmp]$ free -m
             total       used       free     shared    buffers     cached
Mem:          1024        741        282          0          0          0
-/+ buffers/cache:        741        282
Swap:            0          0          0    // no swap is enable on openvz machine;(

Answer 1

top is a tool in linux that shows top processes running, including memory consumption. Open a terminal and give top -c. This will show the processes in random order. To arrange it in order of top processes type shift+p and in order of memory type shift+m. You can find the process id's of processes running by looking at the table. If you want to kill a process press k and give the process id to kill it. Here is a quick read on top

At this same time, if you run this command in a new terminal

watch -n 2 `free -m`` (remove the last quote when you run the command, sorry i just can't get the formatting right here)

you can see real time changes in memory as you work along top command, and if it is freeing up memory. This updates memory stats every two seconds.