🚀 go-pugleaf

>From:    lev@suned1.Nswses.Navy.Mil (Lloyd E Vancil)
> ...
>(I'm not sure that the "service" retains a complete copy of it's
> users "staging file"; after all they claim nearly 1 million
> users and at ~1meg per user that's 10^12 bytes? (wow)  And I'm
> not sure the data from one user is seen by another's machine.)

(wow)?  Not really *that* awesome...

This is only 1 terabyte (1000 gigabytes).  Something the PC world has
to remember is that the mainframe world is *designed* to deal with
*very* large databases.  For instance, we run a medium-large IBM
mainframe shop (1 3090 and 1 3084, maybe 90MIPS between them), and we
have 300 gigabytes of disk here - that's already 30% of that terabyte.
And we're NOWHERE near capacity - rough back-of-envelope calculations
show that a 3090 with 128 I/O channels (say 96 of them for disk, the
rest for TP and tapes and the like) and 256 mod 3390 disks per channel
(at 1.5 gigabytes a disk) can address 36 terabytes of disk storage.
Unless I dropped a decimal point someplace, you'd only need a room
about 250 by 200 feet to store this. (Yes, I know I'm over-simplifying
channel loading and similar constraints - most *real* shops with this
much disk run multiple CPU's, etc etc)

Bottom line - out in the commercial world of major banks, stock
brokerages, insurance houses, airline reservation systems, and other
large corporations, a mere terabyte of disk isn't considered all that
much.
                                  Valdis Kletnieks
                                  Computer Systems Engineer
                                  Virginia Polytechnic Institute