Vmstat
External
Internal
Overview
Reports virtual memory and other system statistics.
Output
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 0 778480 700 156424 0 0 122 4 29 64 0 0 98 0 1
procs
r
The number of runnable processes (running or waiting for run time).
b
The number of processes in uninterruptible sleep. This is the size of the "wait queue" - processes that are waiting for I/O (disk, network, user input, etc.)
memory
swpd
The amount of virtual memory used. Represents how many blocks are swapped out to disk (paged). The same information can be obtained from /proc/swaps. To get the amount of swapped memory, in bytes, multiply the swpd value with the size of the block. This is how you can get the size of the page, in bytes. Is this really true? It contradicts with the data read from /proc/meminfo..
free
The amount of free memory.
buff
The amount of memory used as buffers.
cache
The amount of memory used as cache.
swap
si
Amount of memory swapped in from disk.
so
Amount of memory swapped to disk.
IO
b
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 the clock.
cs
The number of context switches per second.
CPU
Also see:
us
Percentages of total CPU time spent running non-kernel code (user time, not including nice time). Also see /proc/stat cpu user time.
sy
Percentage of total CPU time spent running kernel code (system time). Also see /proc/stat cpu system time.
ni
Percentages of total CPU time spent running niced user processes. Also see /proc/stat cpu nice time.
id
Percentages of total CPU time spent idle (in the kernel idle handler). Also see /proc/stat cpu idle time.
wa
Percentages of total CPU time spent waiting for IO completion. Also see /proc/stat cpu iowait time.
hi
Percentages of total CPU time spent spent servicing hardware interrupts. Also see /proc/stat cpu irq time.
si
Percentages of total CPU time spent spent servicing software interrupts. Also see /proc/stat cpu softirq time.
st
Percentages of total CPU time stolen from this vm by the hypervisor. Also see /proc/stat cpu steal time, Virtualization Concepts - Steal Time.
Continuous Readings
vmstat 1