Welcome to forum!
Yes it is very common on Linux and UNIX commands to consume all free memory. Basically OS caches all frequently used files in memory and server them from memory. Here is output from my system:
Output:
Code:
total used free shared buffers cached
Mem: 2008 1595 412 0 58 718
-/+ buffers/cache: 818 1189
Swap: 1027 0 1027
My system load
Output:
Code:
11:03:29 up 137 days, 11:23, 1 user, load average: 0.16, 0.10, 0.09
Look at the buffers/cache line. In short as long as your load is below 5 (<5) and disk i/o under control nothing to worry
