
Chapter 2. Tuning considerations 19
– free: The amount of idle memory (kB)
– buff: The amount of memory used as buffers (kB)
Swap
– si: Amount of memory swapped in from disk (kB/s)
– so: Amount of memory swapped out to disk (kB/s)
IO
– bi: Blocks received from a block device (blocks/s)
– bo: Blocks sent to a block device (blocks/s)
System
– in: The number of interrupts per second (including clock interrupts)
– cs: Number of context switches per second
CPU
– us: User time (percent of CPU time)
– sy: System time (percent of CPU time)
– id: Idle time (percent of CPU time)
We are particularly interested in swap (paging) rates. The unit of measurement is ...