[comp.sys.dec] IO Programming under VMS, I have a problem!

raisch@Control.COM (Robert Raisch) (03/29/91)

I have a scenerio that I need help with...

	Backgound:  

	Assume that I have a VAX running VMS that is talking to hundreds of
	terminal ports, each of which is connected to a device at 9600bps.
	Some are thru LAT, some thru DECNET, and a few thru Asynch.

	I have 6 new devices I need to add, that all talk Asynch.

	None of the current devices do any sort of polling to the VAX, but
	the new devices will poll the VAX once every couple of seconds.

	Problem:

	I have heard that VMS has a 'feature' that if a process is IO-bound,
	VMS will bump up it's priority, and that the SysAdmin has no control
	over the ultimate priority of the task.

	If a task is VERY IO-bound, it has the possibility of being bumped
	up to a massive priority that will ultimately crash the system.

	IS THIS TRUE??!?!?


Note:  I am not a VMS pern.  My forte is Unix.  I really need to know if this
scenerio is a possibility, as it will DRAMATICALLY effect the design of an
on-going development effort, (both Hardware and Software).

As always, your help is most appreciated.

Regards, Robert.
-- 
"I ate his liver with some fava beans and a nice chianti." -Lector