ok, today i'am going to write on something technical, what load average is all about.. ?
when we are talking about system performance, how fast or slow a system is ( ie, a server or workstation)?
In unix/linux we will use a performance monitoring tools such as top, vmstat, uptime etc..
when we run top or uptime as below :
#uptime
5:10pm up 50 day(s), 2 users, load average: 0.02, 0.02, 0.02
we can see there is an output of load average. So what the hell it's all about? what does it mean?
ok , i tell you what it's all about from my own understanding.. ,
load average = no. of average process /jobs in the run queue over a period of time (1, 5 and 15 min).
so then what?, how i can tell how slow or fast are my machine?,
quote from
http://www.itworld.com/nl/unix_sys_adm/03202002/
"As a general rule of thumb, if load averages consistently exceed three times the number of CPUs on your system, your CPU is overworked. Averages less than 1 are acceptable. "
ok, i hope that explained what load average is all about, if your machine load average is not exceed 3 on a single CPU machine then it ok, but above that you're in trouble, eventhough you CPU is 90% idle... that mean maybe something other than CPU's is keeping the jobs from completing, ie I/O or memory etc..
