Thanks in advance for your help...

The reason I'm asking is that I want to stack my RMAN backups right on
top of each other, the way I do with filesystem backups.  As soon as one
is done, I want the other to go active.  The problem is, though, is that
there will be more RMAN backups running than I have tape drives for.
For filesystem backups, I give them all the same start time and window,
and they start and finish when they get around to it.  What would happen
if I did this with RMAN backups?

What happens if I specify more RMAN backups than I have tape devices
for?  I know that if this were filesystem backups, the others would just
queue, and there would be no issue.  But it seems to me that Oracle can
be picky about having enough tape devices for all simultaneous streams
that it wants to run, and if it doesn't get them all at once, or within
a certain time frame, then the job fails.  I've searched the manuals and
don't see what I'm looking for?  What happens if:

1. The RMAN class starts, but there are NO tape drives
2. The RMAN class starts, but there are less tape drives than needed
   (e.g. the RMAN backup wants four drives, but only three are
available)

How long will RMAN wait until it gives up?  How can I change this value?