How can i check that which process and path of particular file is using
highst Swap space ?
Difficult to tell exactly which processes are using swap, but a good start would be something like:
ps -eo pid,vsz,rss,args | sort -rn -k 2,2 | head -20
This will show you the 20 largest processes sorted by their virtual memory size, largest first. If the vsz column is much larger than rss (resident set size) then that process is a likely candidate for consuming lots of swap.
This is a good question. Linux doesn't provide a good way, AFAIK.
Annihilannic gives a good tip. The thing is, the output might be irrelevant. For instance, my machine uses 4k of swap right now, even though it shows a number of processes with a huge vsz-rss discrepancy.