<snip> Is z/OS unaware of the underlying RAID and designed not to dispatch concurrent operations to what it sees as a single device? </snip>
Correct! With the exception of PAV (which was invented to address the IOSQ issue!) We could get into a long discussion here, but "large" datasets that take up most of a mod 9 will be minimally impacted (without PAV). Many small datasets will exacerbate the issue (without PAV). <snip> With SLEDs, response time would be more likely to increase than decrease, because of increased seek lengths and because of contention. With RAID, things are less predictable.</snip> Agreed! However, the original issue still exists. Accessing 3 times as much data with a single "logical" actuator". PAV merely addresses the IOSQ problem. Cache, RAID, address the service time for the device. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
