System Resource Monitoring


Resources on a computer can become a problem when they aren't monitored correctly. The "Bottlenecks" are

1) CPU performance

2) Memory usage

3) Disk performance

4) Network performance (Discussed in Network Administration)

There are many share ware/free ware and commercial programs out there to monitor and alert you that there may be a problem. Windows NT comes with Performance Monitor, which when configured correctly can alert you to potential problems.

In UNIX the first thing you should check is the load on the machine by typing uptime Uptime will give you Time, Time since last reboot, # of users, #of jobs in run queue in last 1, 5, 15 minutes.

Any loads over 2.0-3.0 should be investigated.

To investigate use ps. PS will give you a list of all active processes running on the system. With certain flags you will get different output, for example, ps -a returns: 

PID TTY      TIME CMD
7199 pts/9   12:45 netscape
7196 pts/5    0:09 rlogin
6488 pts/6    0:00 ps
7195 pts/5    0:00 rlogin
8466 pts/7    0:01 vi
Memory information can be found with ps and swap -l.To interactively watch memory usage use vmstat, or osview. Another outside program that is extremely useful is top. It lists all process and can be configured to update itself at a given interval.

Monitoring disk performance by invoking iostat -v This gives you reads and wites per sec, Kilobyte reads and writes per sec, queue length, ave. Transactions being serviced, ave. Service time, % time the queue is empty, % time disk busy.

Windows NT roles all of the above commands into a GUI interface called Performance Monitor (Perf Mon) located in the Administrative Tools Group. By default the Perf Mon doesn't monitor anything, but by clicking the "+" button you get a objects listing of the following:

Browser, Cache, Logical Disk, Memory, NBT Connections, Objects, Paging File, Physical Disk, Process, Processor, Redirector, Server, Server Work Queues, System, Telephony, and Thread.

Select the object than specify the Counter you want to watch and click ADD. When you are done click DONE. You can save this log for future reference.

Another feature to use is the Windows NT Diagnostics package that is located with Perf Mon under administrative Tools Group. This gives you general info about your NT box and its resources.

One last "home grown" package to help you is the Task Manager, this gives you cpu and memory usage etc. Right Click on the task bar and select Task Manager.