DMOYNIHA%WAYNEST1.BITNET@cornellc.cit.corn (Dennis P. Moynihan) (09/30/89)
We're in the process of reviewing mainframe based Unix systems to
run on our Amdahl 5890 (IBM compatible) processor. We're looking at
bringing in Amdahl's UTS Unix and are reviewing AIX/370. Our central
facility is not currently a unix shop, so I've got a few questions for
the group:
1. What are valid roles for a mainframe based unix system? Obviously
departments have access to increasingly powerful workstations--we're
looking for the right niches for each class machine. Right now
we see a mainframe unix system as a large file server, good for long
running processor intensive tasks, and for handling large number of
trival-task users (i.e. undergrads) cost effectively. Are these valid?
Others that we missed?
2. For those that have selected or are thinking about selecting UTS or
AIX/370, what prompted your decision? What are the general advantages
and disadvantages of each (in your view)?
3. One of our concerns is application integration and porting between
our departmental processors (mostly Ultrix and SUNs) and our mainframe
system. UTS is in lockstep with AT&T developments, while IBM seems
to be claiming that AIX/370 will have the "best" of both System V
and BSD. What are your experiences with or thoughts on porting to
these systems?
We're open to any other general comments you have on mainframe unix
systems and UTS and AIX/370 in particular. Thanks in advance!
--------------------------------------
Dennis Moynihan (DMOYNIHA@WAYNEST1)
Computing and Information Technology
Wayne State University
Detroit, MIjsloan@handies.ucar.edu (John Sloan,8292,X1243,ML44E) (09/30/89)
From article <21015@adm.BRL.MIL>, by DMOYNIHA%WAYNEST1.BITNET@cornellc.cit.corn (Dennis P. Moynihan): > We're open to any other general comments you have on mainframe unix > systems and UTS and AIX/370 in particular. Thanks in advance! I don't have any experience specifically with either UTS or AIX, but I do have a few general comments (although from your questions I bet you've already considered them). My perspective is that I spent years as a systems programmer on IBM mainframes (360/65 and 370/3031) under a variety of OSs (OS/MFT, MVT, SVS, MVS); for the past five or six years I've been dealing almost exclusively with UNIX (both BSD and System V). I personally know of two AIX/370 shops, who chose AIX just because they had IBM hardware and hence had IBM support. You may end up using UTS for the same reason. One thing IBM/compatible mainframes are really good at is providing I/O bandwidth, which makes them REALLY attractive as file servers. You may want to consider though, that much of that bandwidth exists in the communication paths between CPUs, channels, and controllers. Once you leave this optimized I/O path, you may find that the channel and/or network speed is not all that fast in comparison. If you use the mainframe as a fileserver over traditional access paths (i.e. Ethernet) then it may turn out you've got this I/O path the width of the Mississippi, all funneling through 2 inch diameter pipe. In those hazy times when I thought about using a mainframe as a file server, I've wondered if there was hardware to channel attach a FDDI-based fiber network; if not, then a way to channel attach multiple Ethernet interfaces, making each interface look to the outside world as if it were attached to a separate file server (different Internet host ids, etc.). I'd probably like to spread those Ethernet interfaces across several channels, too. Depending on the statistical distribution of channel usage for disks, tapes, Ethernet, etc. I might want to try to optimize the combinations (if possible). Finally, do you really need to run UNIX at all? Some possibilities: o Run AIX/UTS as the native operating system. o Run AIX/UTS under VM as a guest operating system. o Run AIX/UTS under PR/SM. o Run TCP/IP+NFS on top of MVS. This latter alternative doesn't give you a big UNIX timesharing engine, but it retains MVS functionality, without the overhead of VM or PR/SM, and could still let you use the big iron as a file server (no claims are made, though, about mapping UNIX file system semantics on top of an MVS VSAM-based file system). There are also network bandwidth/management issues regarding centralizing a heavily-used file server resource; some of those same issues crop up when you just put all your Sun (or whatever) file servers off the same network cable (e.g. together in a computer room). As you come to conclusions, you would be doing the net a service by posting a summary. I for one would be really interested in hearing what you've decided, how you came to your decision, and how it all works out in the end. I hope that eventually EDUCOM publishes another volume similar to their ancient _Campus Computing Strategies_ and their more recent, excellent, _Campus Networking Strategies_, which covers some of these very issues with case studies. Maybe a _Campus Integration Strategies_. John Sloan NCAR/SCD NSFnet: jsloan@ncar.ucar.edu P.O. Box 27588 P.O. Box 3000 NCAR Mesa Lab, Room 42A Lakewood CO 80227 Boulder CO 80307 +1 303 497 1243 Logical Disclaimer: belong(opinions,jsloan). belong(opinions,_):-!,fail.
KJH%APLVM.BITNET@cornellc.cit.cornell.edu (Kenneth J. Heeres) (09/30/89)
We had UTS installed at our system and have removed it. We are very much
interested in mainframe UNIX but see it in a role as server (file, database,
compute, etc). UTS had very poor network support and good 3270 terminal
support. UTS/580 appears to be much better at network support. AIX has no
3270 terminal support but it does appear to have good network support. We
would love to have either AIX/370 or UTS/580 in house. Unfortunately the
fees are too much for us to justify. We are going to experiment with
TCP/IP under MVS and VM instead. I would be very interested in any
comments you get back.
Kenneth J. Heeres
The Johns Hopkins University
Applied Physics Laboratory