[daip] Tape drives in AIPS

[Eric Greisen]

Michael Reid writes:
 > 	I am having a problem using a tape drive under AIPS and I was
 > hoping someone could help me.  I have AIPS installed on one machine but
 > the tape drive is on another machine (both are running Solaris, if it
 > makes a difference).  I am trying to use AIPS on the first machine to read
 > from the tape drive on the second.  This is not working--AIPS on the first
 > machine doesn't seem to recognize that there IS a tape drive on the other
 > machine.  According to section 3.9.3 of the AIPS cookbook, I should have
 > AIPS installed on BOTH machines for this to work.  This is problematic for
 > two reasons: the computer with the tape drive on it is too old to run AIPS
 > very well and has very limited disk space, so we really don't want AIPS
 > installed on it, and, more importantly, our tech support people promised
 > to have the head of the next astronomer who asked them to install AIPS on
 > a new machine.

       The question is more one of architecture.  We have about 100
Linux boxes all running off 1 copy of AIPS which each mounts.  That
same copy, with a different tree for the binary parts also supports
the remaining Solaris machines.  In other words, AIPS does not need to
be installed on machines similar enough to run the same binaries.  But
the TPMON task must run on the machine that owns the tape drives.  The
other machine talks to TPMON which talks to the local devices.

 > 
 > 	Is there some way to cause AIPS to recognize the remote tape drive 
 > _without_ installing AIPS on both machines?  Failing that, can I read the 
 > data off the tape some other way and still be able to read it into AIPS 
 > off the hard disk?  (If so, how do I do that?)  

It depends somewhat on the type of data whether this works all that
well.  VLBA Correlator data are really best read from a multi-file
FITS tape.  But even with that format, the DOCONCAT adverb does allow
for reading the files in separate runs of the task.  You can run dd on
the machine that has the tape device and write or ftp/copy the file to
your AIPS machine.  Then the INFILE adverb in FITLD, IMLOD, UVLOD, and
even FILLM (for 31DEC03 aips) will allow the file to be read from disk
rather than tape.  FILLM will read multiple files if their names are
appropriate, e.g. file_1, file_2, file_3, etc.

Eric Greisen