Understand Linux Load Averages and Monitor Performance of Linux

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- What is LoadAvg ?:

   Load average – is the average system load calculated over a given period of time of 1, 5 and 15 minutes.
   In Linux, the load-average is technically believed to be a running average of processes in it’s (kernel) execution queue tagged as running or uninterruptible

- Understanding System Average Load
  sử dụng command "w" đê xem thông tin load của server :

23:16:49 up 10:49, 5 user, load average: 1.00, 0.40, 3.35

 On a single core system this would mean:
- The CPU was fully (100%) utilized on average; 1 processes was running on the CPU (1.00) over the last 1 minute.
- The CPU was idle by 60% on average; no processes were waiting for CPU time (0.40) over the last 5 minutes.
- The CPU was overloaded by 235% on average; 2.35 processes were waiting for CPU time (3.35) over the last 15 minutes.
On a dual-core system this would mean:
- The one CPU was 100% idle on average, one CPU was being used; no processes were waiting for CPU time(1.00) over the last 1 minute.
- The CPUs were idle by 160% on average; no processes were waiting for CPU time. (0.40) over the last 5 minutes.
- The CPUs were overloaded by 135% on average; 1.35 processes were waiting for CPU time. (3.35) over the last 15 minutes.

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