Checking Linux Memory usage
# free -m
Shows the current memory usage, formatted in MB
# cat /proc/meminfo
Check the values of MemTotal, MemFree, Buffers, Cached, SwapTotal, SwapFree.
They indicate same values of memory usage as the free command above.
Once you’ve got a handle on the values and system usage, you can attempt to reduce the footprint,
# sync; echo 1 > /proc/sys/vm/drop_caches
Clear dentries and inodes
# sync; echo 2 > /proc/sys/vm/drop_caches
Clear PageCache, dentries and inodes
# sync; echo 3 > /proc/sys/vm/drop_caches
Force Swapfile to clear
#swapoff -a && swapon -a
This will disable and re-enable the SWAP Cache, it may take a while to process this command.