vmstat is a wonderful tool, whose output is a bit cryptic for the faint of the heart. Proc -– r: Processes actually running, waiting for some attention from the CPU b: Uninterruptble sleeping processes (This I am yet to discover what does it mean) Memory: -– swpd: Virtual memory usage (swap areas are listed in /proc/swaps) free: Idle memory buff: Memory used as buffers, like before/after IO operations, I guess…

This shows the power of a well set hard disk controller: BEFORE: johnny:~# hdparm -tT /dev/hda /dev/hda: Timing buffer-cache reads: 128 MB in 0.58 seconds =220.69 MB/sec Timing buffered disk reads: 64 MB in 8.89 seconds = 7.20 MB/sec AFTER: /dev/hda: Timing buffer-cache reads: 128 MB in 0.60 seconds =212.66 MB/sec Timing buffered disk reads: 64 MB in 1.57 seconds = 40.72 MB/sec PS: The second test was made when the machine was under production.…