braun@dri.com (Karl T. Braun (kral)) (10/30/90)
We are currently running a Dual System MV3400 with 4 RF31s on the DSSI. In doing some [rare] forward planning, I was wondering if it might be possible in the future to split up the configuration so that one machine is running Ultrix and the other is still running VMS. My two major concerns at this point are: 1) Can Ultrix make use if the DSSI bus? 2) Is it possible for for Ultrix disks and VMS disks to reside on the same DSSI bus, even though each O/S can't access the disks of the other w/o goign through the owning host? Any info, or even speculation, is welcome. -- kral * 408/647-6112 * ...!uunet!drivax!braun * braun@dri.com That which does not kill us Makes us stronger - Nietzche
alan@shodha.enet.dec.com ( Alan's Home for Wayward Notes File.) (10/31/90)
In article <KJCS3PZ@dri.com>, braun@dri.com (Karl T. Braun (kral)) writes: > > 1) Can Ultrix make use if the DSSI bus? The DSSI was supported starting in ULTRIX V3.1 if I rememeber correctly. > > 2) Is it possible for Ultrix disks and VMS disks to reside on the > same DSSI bus, even though each O/S can't access the disks of the other > w/o goign through the owning host? This is the DEC side of speaking, though I certainly don't represent DEC on the matter. I just work here.... This is the tough one. It certainly isn't supported. It probably isn't even tested. If you try it and something breaks then it's your problem. Be sure to have good backups before testing it. This is speculation... If you're feeling brave shutdown both VMS systems and write protect the VMS RF's you don't want to touch. I've never had my hands on a real system with DSSI disks, but I'll assume there is a write-protect switch there somewhere. Install ULTRIX on the other system. If that much works, then it will probably work with the other VMS system running. Do lots of testing with both systems up, but don't do any useful work in case it breaks. If you're satisfied that it seems to work, enjoy. If it runs, you have a configuration that looks very much like an ULTRIX and VMS system on the same CI. Don't assume that mounting a disk from one systems shuts out access from the other. The VMS system may still be able to access the ULTRIX disks and ULTRIX the VMS disks. I don't know if the RF series supports exclusive access. I wouldn't want to find out the hard way. > > Any info, or even speculation, is welcome. > > > -- > kral * 408/647-6112 * ...!uunet!drivax!braun * braun@dri.com -- Alan Rollow alan@nabeth.enet.dec.com