Re:Four Facts Millennials Need to Know About the Mainframe (...
by DrScump on Monday April 08, 2019 @12:34AM
(#19602119)
"Since mainframe computers are almost always running at 100% utilization..."
That's essentially impossible, as either CPU or I/O will bottleneck first and be the limiting factor.
As an operator, I used to make note of how different jobs used resources so I could keep overall utilization as high as possible, blending I/O bound jobs with CPU heavy jobs. (This was graveyard shift, where real-time users were few)
There was a great Boole and Babbage product called Resolve that allowed the operator (or a TSO user) to dynamically change job priorities as desired.
That's essentially impossible, as either CPU or I/O will bottleneck first and be the limiting factor.
As an operator, I used to make note of how different jobs used resources so I could keep overall utilization as high as possible, blending I/O bound jobs with CPU heavy jobs. (This was graveyard shift, where real-time users were few)
There was a great Boole and Babbage product called Resolve that allowed the operator (or a TSO user) to dynamically change job priorities as desired.