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
cache: Memory used as cache.

Swap:
-–
si: Memory swapped in from the disk
so: Memory swapped to the disk

IO:
-–
bi: Blocks received from block device (like a hard disk)
bo: Blocks sent to a block device

System:
-–
in: The number of interrupts per second, including the clock.
cs: The number of context switches per second.

CPU:
-–
us: Time spent running non-kernel code. (user time, including nice time)
sy: Time spent running kernel code. (system time - network, IO interrupts, etc)
id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time.
wa: Time spent waiting for IO. Prior to Linux 2.5.41, shown as zero.

You should get used to monitor this data, to see how is your system going during peak usage time.

Archived Comments

Hi Admin,

It’s nice to new learner like me, but… Anonymous - Jul 6, 2008

Hi Admin,
It’s nice to new learner like me, but still I do not understand few information like below mentioned synonym.
mf
pi
po
fr
de
sr
m0
m1
m2
m3
m7
in
sy
cs
us
When I did vmstat 5 5 i dot following details

kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr m0 m1 m3 m7 in sy cs us sy id
0 0 0 13948448 1184032 59 178 363 44 47 0 6 2 1 0 1 805 7729 2584 7 3 90

b is for blocked - process is waiting for in example write to disk.

b is also known as “Wait Queue”

check this URL for more info.
http://perumal.org/analyzing-database-server-io-bottlenecks-using-iostat/

Thanks,
Jay
chandranjoy@gmail.com
http://innovationframes.com/phpbb

Nice, thanks. Direct copy from the man pages without a clear explanation. Your a real gem.

nice !