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Xah Lee's Unixism

Anne & Lynn Wheeler lynn at garlic.com
Thu Sep 9 11:02:33 EDT 2004 
Morten Reistad <firstname at lastname.pr1v.n0> writes:
> But with a PM you had to do a cold start. All the disks had to be
> spun down, filters changed, and they had to spin for an ungodly long
> time after the filter change before heads could be enabled
> again. This was to bring all the dust that was let loose in the
> process into the new filters before heads went to fly over the
> platters again.
>
> Also power supplies had to be checked for the dreaded capacitor
> problems. Tape drives also had these. This was industry-wide
> problems; and news from a few burned UPS'es the last couple of
> months tell me that the capacitor problems are still with us.
>
> It was a real accomplishment when we in 1988 could do a full PM
> (Prime gear) without shutting down the system. All disks were
> mirrored, and all power duplicated, so we shut down half of the
> hardware and did PM on that; and took the other half next week.
>
> SMD filters were used at a quite high rate; even inside well
> filtered rooms. ISTR 6 months was a pretty long interval between
> PM's.

360s, 370s, etc differentiated between smp ... which was either
symmetrical multiprocessing or shared memory (multi-)processing
... and loosely-coupled multiprocessing (clusters).
http://www.garlic.com/~lynn/subtopic.html#smp

in the 70s, my wife did stint in POK responsible for loosely-coupled
multiprocessing architecture and came up with peer-coupled shared
data
http://www.garlic.com/~lynn/subtopic.html#shareddata

also in the 70s, i had done a re-org of the virtual memory
infrastructure for vm/cms. part of it was released as something called
discontiguous shared memory ... and other pieces of it was released
as part of the resource manager having to do with page migration
(moving virtual pages between different backing store devices).
http://www.garlic.com/~lynn/subtopic.html#fairshare
http://www.garlic.com/~lynn/subtopic.html#wsclock
http://www.garlic.com/~lynn/subtopic.html#mmap
http://www.garlic.com/~lynn/subtopic.html#adcon

in the mid-70s, one of the vm/cms timesharing service bureaus
http://www.garlic.com/~lynn/subtopic.html#timeshare

was starting to offer 7x24 service to customers around the world; one
of the issues was being able to still schedule PM .... when there
was never a time that there wasn't anybody using the system. they
had already providing support for loosely-coupled, similar to
HONE
http://www.garlic.com/~lynn/subtopic.html#hone

for scallability & load balancing. what they did in the mid-70s was to
expand the "page migration" ... to include all control blocks ...  so
that processes could be migrated off one processor complex (in a
loosely-coupled environment) to a different processor complex ...  so
a processor complex could be taken offline for PM.

in the late '80s, we started the high availability, cluster multiprocessing
project:
http://www.garlic.com/~lynn/subtopic.html#hacmp

of course the airline res system had been doing similar things on 360s
starting in the 60s.

totally random references to airline res systems, tpf, acp, and/or pars:
http://www.garlic.com/~lynn/96.html#29 Mainframes & Unix
http://www.garlic.com/~lynn/99.html#17 Old Computers
http://www.garlic.com/~lynn/99.html#100 Why won't the AS/400 die? Or, It's 1999 why do I have to learn how to use
http://www.garlic.com/~lynn/99.html#103 IBM 9020 computers used by FAA (was Re: EPO stories (was: HELP IT'S HOT!!!!!))
http://www.garlic.com/~lynn/99.html#136a checks (was S/390 on PowerPC?)
http://www.garlic.com/~lynn/99.html#152 Uptime (was Re: Q: S/390 on PowerPC?)
http://www.garlic.com/~lynn/2000b.html#20 How many Megaflops and when?
http://www.garlic.com/~lynn/2000b.html#61 VM (not VMS or Virtual Machine, the IBM sort)
http://www.garlic.com/~lynn/2000b.html#65 oddly portable machines
http://www.garlic.com/~lynn/2000c.html#60 Disincentives for MVS & future of MVS systems programmers
http://www.garlic.com/~lynn/2000e.html#21 Competitors to SABRE?  Big Iron
http://www.garlic.com/~lynn/2000e.html#22 Is a VAX a mainframe?
http://www.garlic.com/~lynn/2000f.html#20 Competitors to SABRE?
http://www.garlic.com/~lynn/2001.html#26 Disk caching and file systems.  Disk history...people forget
http://www.garlic.com/~lynn/2001b.html#37 John Mashey's greatest hits
http://www.garlic.com/~lynn/2001d.html#69 Block oriented I/O over IP
http://www.garlic.com/~lynn/2001e.html#2 Block oriented I/O over IP
http://www.garlic.com/~lynn/2001g.html#35 Did AT&T offer Unix to Digital Equipment in the 70s?
http://www.garlic.com/~lynn/2001g.html#45 Did AT&T offer Unix to Digital Equipment in the 70s?
http://www.garlic.com/~lynn/2001g.html#46 The Alpha/IA64 Hybrid
http://www.garlic.com/~lynn/2001g.html#47 The Alpha/IA64 Hybrid
http://www.garlic.com/~lynn/2001g.html#49 Did AT&T offer Unix to Digital Equipment in the 70s?
http://www.garlic.com/~lynn/2001j.html#17 I hate Compaq
http://www.garlic.com/~lynn/2001n.html#0 TSS/360
http://www.garlic.com/~lynn/2001n.html#3 News IBM loses supercomputer crown
http://www.garlic.com/~lynn/2002c.html#9 IBM Doesn't Make Small MP's Anymore
http://www.garlic.com/~lynn/2002g.html#2 Computers in Science Fiction
http://www.garlic.com/~lynn/2002g.html#3 Why are Mainframe Computers really still in use at all?
http://www.garlic.com/~lynn/2002h.html#12 Why did OSI fail compared with TCP-IP?
http://www.garlic.com/~lynn/2002h.html#43 IBM doing anything for 50th Anniv?
http://www.garlic.com/~lynn/2002i.html#63 Hercules and System/390 - do we need it?
http://www.garlic.com/~lynn/2002i.html#83 HONE
http://www.garlic.com/~lynn/2002j.html#83 Summary: Robots of Doom
http://www.garlic.com/~lynn/2002m.html#67 Tweaking old computers?
http://www.garlic.com/~lynn/2002n.html#29 why does wait state exist?
http://www.garlic.com/~lynn/2002o.html#28 TPF
http://www.garlic.com/~lynn/2002p.html#58 AMP  vs  SMP
http://www.garlic.com/~lynn/2003.html#48 InfiniBand Group Sharply, Evenly Divided
http://www.garlic.com/~lynn/2003c.html#30 diffence between itanium and alpha
http://www.garlic.com/~lynn/2003d.html#67 unix
http://www.garlic.com/~lynn/2003g.html#30 One Processor is bad?
http://www.garlic.com/~lynn/2003g.html#32 One Processor is bad?
http://www.garlic.com/~lynn/2003g.html#37 Lisp Machines
http://www.garlic.com/~lynn/2003j.html#2 Fix the shuttle or fly it unmanned
http://www.garlic.com/~lynn/2003k.html#3 Ping:  Anne & Lynn Wheeler
http://www.garlic.com/~lynn/2003n.html#47 What makes a mainframe a mainframe?
http://www.garlic.com/~lynn/2003p.html#45 Saturation Design Point
http://www.garlic.com/~lynn/2004.html#24 40th anniversary of IBM System/360 on 7 Apr 2004
http://www.garlic.com/~lynn/2004.html#49 Mainframe not a good architecture for interactive workloads
http://www.garlic.com/~lynn/2004.html#50 Mainframe not a good architecture for interactive workloads
http://www.garlic.com/~lynn/2004b.html#6 Mainframe not a good architecture for interactive workloads
http://www.garlic.com/~lynn/2004b.html#7 Mainframe not a good architecture for interactive workloads
http://www.garlic.com/~lynn/2004c.html#35 Computer-oriented license plates
http://www.garlic.com/~lynn/2004e.html#44 Infiniband - practicalities for small clusters
http://www.garlic.com/~lynn/2004f.html#58 Infiniband - practicalities for small clusters
http://www.garlic.com/~lynn/2004g.html#14 Infiniband - practicalities for small clusters

-- 
Anne & Lynn Wheeler | http://www.garlic.com/~lynn/
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