Here is the summary from 'top' command
top - 20:14:50 up 18 days, 23 min, 1 user, load average: 0.22, 0.20, 0.18 Tasks: 99 total, 1 running, 98 sleeping, 0 stopped, 0 zombie Cpu(s): 1.1%us, 0.1%sy, 0.0%ni, 94.2%id, 3.5%wa, 0.0%hi, 0.0%si, 1.2%st Mem: 2092032k total, 471684k used, 1620348k free, 924k buffers Swap: 4194296k total, 153940k used, 4040356k free, 42564k cached
As you can see, out of 2GB memory just around 461MB is used. At the same time it shows 150MB of swap is used.
How is this possible? Why would my server hit swap if there's physical memory free?