... So, I ask, is I/O tuning still possible, or even necessary? ... I've got a related question. Our service provider is attempting to get us more channels into our single DASD controller. We have four. We have no Channel Busy Delay. We have more than adequate response time. They have supplied no evidence, as yet.
My question is: What is considered “too busy” these days for channels? With the advent of all the changes to the channel sub-system since XA (and onward), I believe you can run them quite high, well over 50%. Since (the simple equation), the odds of all four being busy is: .5 ** 4 = .125 Or 12.5% of the time there would be no channel busy. Of course, you have to calculate the 'Relative Path Busy', since your own I/O doesn't count. But, I did say 'simple'. And, I don't intend this to become a statistical discussion, nor a queueing theory one, either. The bottom line is we have no channel busy delay yet; our service provider is telling us we need more channels; we have seen no evidence; when would somebody OUT THERE consider their channels “too busy”? -teD (The secret to success is sincerity. If you can fake that, you've got it made!) ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
