The free command helps in getting the memory usage in the system
[rams@stopprepare-lx ~]$ free -m
total used free shared buffers cached
Mem: 1002 985 17 0 93 380
-/+ buffers/cache: 512 490
Swap: 2055 0 2055
Total Memory in the system : 1002M =~ 1GB
Total Memeory Used : 985M
From the second line we understand that out of the 985M, only 512M is actually used. The remaining 490M is used for buffers and cache. This 490M is actually free for application consumption.
So, free memory is 490M+17M
Also, 490M usage breakup for buffers and cache is 93M+380M.
The most important part of this listing for assessing performance is the Swap line; this shows us that we aren’t currently using any swap, which suggests that we don’t really have any memory problems at the moment. The system is able to fit everything into physical memory without having to resort to slow, disk-based swap space.