[daip] AIPS user data areas

[computer support]

>Date: Fri, 10 Jan 2003 17:54:31 -0700
>From: Eric Greisen <egreisen at cv3.cv.nrao.edu>
>To: computer support <help at astro.ucla.edu>
>Cc: daip at cv3.cv.nrao.edu
[...]
>    Good.  Now change the + signs above to minus signs.  Then a user
>on mimosa will get only the mimosa disks unless he/she specifically
>asks for others via a (for example) da=osprey on the aips start-up
>command line.  The mimosa disks will be fast on mimosa, the osprey
>disk on osprey, etc.

I'm surprised, because I thought that at least one disk had to be 
required ("+" entry), based on instructions read long ago.  Also, 
we found problems if that disk was not writable by any AIPS user 
ID ("no disk available" or something like that)...

> > Can you tell me what we should change to make this more optimal?
> > 
> > Also, suppose that one of the remote systems (say the "PUBLIC" one) is down
> > for a few days due to hardware failure.  How will that affect the catalog
> > numbering and such that was worrying Jean?
>
>In the scheme I recommend, the PUBLIC disks will only be used on
>public except as specifically requested.  If it is down then the
>request will be ignored, but the disks are at the high number end of
>things in that case.
>
>Jean had some specific problem by which she was failing to get access
>to existing data.  I forget what it was.  Since I had not heard from
>her I assumed that that glitch had been solved.

Her problem was that, if a disk ahead of hers in our list was 
unavailable, the number of her disk (and therefore her catalog 
file names or whatever) would change and she wouldn't find.  
It seems that making no disks required will make this worse, 
as the numbering will now vary even more, depending on what 
hosts are given to the "da=" command line option.  

But maybe I'm missing something.  We'll try it that way...
Anyway, thanks for your prompt reply on Friday.

Philippe