In <[EMAIL PROTECTED]>, on 07/19/2005
at 07:48 AM, Steve Comstock <[EMAIL PROTECTED]> said:
>I've been trying to do a little research and
>I'm getting mixed results. What I would like
>to find is: what is the capacity of the largest
>logical 3390 model supported by z/OS?
The Devil is in the details. Some facilities put an artificial limit
on, but there is an absolute cap of 16Ki cylinders, i.e., 983040
tracks. So to allow, e.g., a 200 GB drive to be a single logical
volume, IBM would have to change the geometry by going to a larger
number of tracks per cylinder. Increasing the track size wouldn't do
it because it's already near the limit.
Alternatively, IBM could come up with new DASD architectures, GCKD and
GFBA, in which the fields that are currently 16 bits would be 32 or 64
bits. Obviously a lot of software would have to be changed.
>Figures I've seen range from 8.5 GiB to 55 GiB,
>from different sources.
Refering to different things. Also, if you do the arithmetic I believe
that you will get a value of[1] 55 GB, not 55 GiB.
[1] Well, assuming full track formatting; for realistic formatting
you'll get less.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)
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