On 2/23/06, Brian Nielsen <[EMAIL PROTECTED]> wrote: > If I have multiple z/OS guests connected to independent Guest LANs under > z/VM, can they all safely use the same CHPID value on the NICDEF (good) or > do they all have to be unique (bad)? I think the answer is they can > share, but want to confirm it.
This thing even confused the people who wrote the documentation... My understanding is that z/OS will make assumptions about topology of the network based on the CHPID. So if z/OS finds two NICs with the same CHPID, it will assume they connect to the same OSA. Now if you were to connect the z/OS guest to both dedicated OSA and Guest LAN, you would need to make sure they are on different virtual CHPID, and since you cannot tweak the one of the dedicated OSA, you pick the CHPID of the virtual NIC different from any real OSA in the machine, just in case... And apparently there's also options for confusion in z/OS when the virtual NIC is on the same CHPID as another device. So this is an upper boundary for the number of different Guest LANs each z/OS can connect to. Those CHPIDs restrictions are within a single z/OS guest. I have no idea whether a virtual parallel sysplex would make two z/OS guests share confusion about CHPIDs, but otherwise you would be free there. For simple systems management it might make sense to keep them the same though... Rob -- Rob van der Heij Velocity Software, Inc
