loadavg utility

General form:

loadavg [-a] delay samples

The loadavg utility displays a number of samples of the system load. It is similar to the Unix sar command and shows a subset of the information that is displayed by the Connection Manager's Current system load page.
Metrics that are displayed include:-

• User :- Percentage of CPU time spent executing user code.
• Sys :- Percentage of CPU time spent executing system calls.
• Wait :- Percentage of CPU time spent waiting for disk I/O.
• Idle :- Percentage of CPU time spent doing nothing.
• RunQ :- Real-time processor run queue.
• WaitQ :- Number of processes waiting on disk I/O.
• Phys Mem :- Amount of RAM installed in the system.
• Used Mem :- Amount of memory used by running processes.
• Free Mem :- Amount of memory available to execute processes, this does not include memory used for the operating system's file cache.
• Mem usage :- Percentage of memory used.

Example: Show 5 samples taken 2 seconds apart:

$ loadavg 2 5
CentOS release 5.9 (Final) Linux 2.6.18-348.12.1.el5 (myserver.domain.com) 4 CPU
Time     User   Sys     Wait    Idle    RunQ    WaitQ   Phys Mem        Used Mem        Free Mem        Mem usage
15:26:17 0.13%  0.00%   0.00%   99.87%  1.00    0.00    7982Mb          3233Mb          4749Mb          40.50%
15:26:19 2.24%  2.61%   12.81%  82.34%  1.00    0.50    7982Mb          3240Mb          4742Mb          40.59%
15:26:21 5.38%  3.00%   16.62%  75.00%  2.00    0.50    7982Mb          3248Mb          4734Mb          40.69%
15:26:23 65.55% 23.13%  2.36%   8.96%   5.50    0.00    7982Mb          3405Mb          4577Mb          42.66%
15:26:25 37.37% 61.24%  0.00%   1.39%   9.00    0.00    7982Mb          3505Mb          4477Mb          43.91%
Average: User   Sys     Wait    Idle    RunQ    WaitQ   Phys Mem        Used Mem        Free Mem        Mem usage
         22.14% 17.91%  6.38%   53.57%  3.70    0.20    7982Mb          3327Mb          4655Mb          41.68%
Run queue lengths:
        1 min = 1.180000
        5 min = 0.300000
        15 min = 0.090000

An optional -a flag can be used to display all available statistics. In addition to the above, these include:-

• Read :- Rate at which data is being read from disk.
• Write :- Rate at which data is being written to disk.
• Recv :- Amount of network traffic read since the start of the sample.
• RxRate :- Rate at which network traffic is being read.
• Trans :- Amount of network traffic sent since the start of the sample.
• TxRate :- Rate at which network traffic is being written.
• Swap :- Size of the swap file.
• SwUsed :- Amount of memory that has been paged out to the swap file.
• SwFree :- Amount of space left in the swap file.
• Swap usage :- Percentage of swap file in use.