Why is all of my RAM being used?

This question is asked frequently in the forums. If your RAM is being almost fully utilized this is normal behavior for Linux. Run the following commands:

# free
             total       used       free     shared    buffers     cached
Mem:        385404     287484      97920          0      14708     188740
-/+ buffers/cache:      84036     301368
Swap:       786424          0     786424

top - 10:21:24 up  3:04,  1 user,  load average: 0.00, 0.00, 0.00
Tasks: 111 total,   2 running, 109 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:    385404k total,   287604k used,    97800k free,    14784k buffers
Swap:   786424k total,        0k used,   786424k free,   188828k cached

You will notice in both outputs of the listed commands that the Swap usage is 0k and the the Memory is 385404k, 287604k used but of that 188828k is cached.

Please run these commands and look at swap and cached before freaking out.