On Wed, Sep 04, 2002 at 05:07:04PM -0400, Dave Myers wrote: > > > Suggestions for design? > > > > Dedicate two of the adapters to Linux guests and use guest LANs to connect > > VM TCP and the z/OS systems. Use CTC interfaces in Linux guests to connect > > to the VSE and OS/390 systems. Keep the 3rd adapter in case you have to do > > SNA. > > > > > David, > Could you expand on this alittle? > > Why dedicate two adapters to Linux guests (assuming you mean guests under > z/VM). > Why not run these Linux "routers" in dedicated LPARs and isolate them > from other images?
You could do it that way, but again, it's a matter of size. An H50 doesn't have a lot of resources to go around, and LPARs tie up resources in ways that are a pain to work around. Given the scenario you describe below with lots of different programmers fooling around, you don't want to have to wait for everyone to agree on a time to take the various LPARs down. I know that LPARs have gotten a lot more flexible over time, but they're still not as flexible as VM. > And...I don't know enough yet about z/VM, excuse my ignorance...but why is > there > a z/VM guest and then a separate z/VM TCP guest?? Sorry, wasn't completely clear. The VM TCPIP machine runs inside the z/VM or VM guests and provides TCP services to that copy of CP, just like TCP is a started task on other OSes. There isn't a separate VM instance for TCP. > Also...let's assume that my sandbox will be shared by numerous sysprogs > who have different opsys backgrounds. Some OS/390 heavies, some VM, some VSE > etc.... > In that scenario, wouldn't it make more sense to use LPARs to isolate > the OS/390, z/OS, and VSE images, so that these sysprogs don't stomp on each > other ? No reason to use LPAR here. They all stay in their virtual machines, and they can do anything they want without stepping on each othe, including dynamically changing the size and machine configuration of their virtual machine at any time within limits that you set. Nobody touches the real hardware, and nobody has a chance to screw something up for someone else. Much better deal all around. > Given that scenario, what network setup would make more sense? If you have a bigger machine than a H50, use the Linux systems in separate LPARs to isolate the router from the OSes it is routing. For the H50 that you have, run VM in basic mode on the iron and dedicatete the adapters to Linux guests running under that VM as routers, and run everything else as VM guests. -- db
