sar

Sar

The sar command is very versatile in that it can be used to read from logged data, or from real time data. Without time and interval parameters sar will read the daily figures.

The syntax for the sar command varies from Unix to Unix but the following information should be available via one of the options

CPU utilization

%user	percentage of utilization in user mode
%sys	percentage of utilization in system mode
%wio	percentage idle with some process waiting for i/o
%idle	percentage of idle besides waiting for i/o

Buffer Activity

Disk Activity

device	logical name of the device
%busy	portion of time device was busy servicing a request. Should be less than 20%
avque	average number of requests outstanding for the device
R+wls	number of data transfers per second from and to the device
blks/s	number of bytes transferred (in 512-byte units) from and to the device
avwait	verage time (in milliseconds) that transfer requests waited idly on queue for the device
avserv	average time (in milliseconds) to service each transfer request for the device.

System Calls

Swapping/switching activity Should be zero

swpin/s	process swapins per second
swpot/s	process swapouts per second
bswinls	number of 512-byte units transferred for swapins per second
bswotls	number of 512-byte units transferred for swapouts per second
pswchls	number of process context switches per second.

Average queue length

runq-sz	average length of the run queue of processes Should be less than 1.0, but has been see in the high hundreds without users complaining.
%runocc	the percentage of time the run queue was occupied by processes
swpq-sz	average length of the swap queue of runnable processes
%swapocc	the percentage of time the swap queue of runnable processes was occupied