Managing memory with vmstat

A different aspect of memory management can be achieved by using the vmstat command. Considered to be a summary reporting feature associated with memory, processes, and paging, vmstat can be seen in action by typing:

# vmstat -a

Having used the -a option to call on all active and inactive memory, the most endearing columns shown under vmstat's output are best described as follows:

• si: This column shows the value swapped in from disk
• so: This column shows the value swapped out to disk
• bi: This column shows the value sent to block devices
• bo: This column shows the value received from block devices
• us: This column shows the user time
• sy: This column shows the system time
• id: This column shows the idle time

The display does look quite confusing to begin with, but for our purposes, we want to concentrate on the following columns contained under the swap column:

free           si   so
1645452          0    0

Where free shows the current allocation of free memory, si shows...