Don Mulvey wrote: >Also, I think your suggested configuration was to have striping equal the >number of channel paths to the device. Would it not be more desirable to >have each physical volume on a separate control unit with multiple channel >paths to each control unit? This would seem to lessen the chance of >getting channel busy back when trying to read/write a stripe to its device.
For mainframe DASD with 3990 controls and before, it would be a good idea to spread physical volumes such that the maximum number of control units and channels paths are used for a stripe. For RVA, with where control units are basically a software implmentation, you need only maximize channel paths. For Shark, again, you need to maximize spread of LCU (1 LCU=1 raid array) and over channels. For a shark, for example, you might have 32 volumes on 16 LCU's (raid arrays) across 32 channels, so your LVM volume could be 32 stripes. I know that 16 physical volumes over 16 LCU's on 16 channels does work. Regards, Jim Linux S/390-zSeries Support, SEEL, IBM Silicon Valley Labs t/l 543-4021, 408-463-4021, [EMAIL PROTECTED] *** Grace Happens ***
