[daip] problem with big disks (fwd)

[Eric Greisen]

Josh Winn writes:
 > Hi,
 > 
 >   I'm still having a problem using AIPS on a large disk drive (see below).  
 > Have you ever seen this bug, and can you help me to fix it?

     Yes I have seen this - I even wrote the code that produces the
error message.  You do not say what sort of computer you are using and
- most importantly - what level of the operating system.  AIPS C
routines must all be compiled with a special parameter set in the
CCOPTS.SH file

      COMP="-c $OPT0 -I$INC -D_FILE_OFFSET_BITS=64"

and then all the tasks compiled and linked.  This parameter has been
in the CCOPTS.SH for everybody only since the middle of last year (in
the 31DEC01 release).  It was documented in that file for use by the
AOC but not implemented for others - I was afraid that its use on old
Linux machines would cause problems (which it turns out it does not).

Either your system was not built with these options - or you are still
running a Linux with the older kernel (< 2.4 I think).  The RedHat
releases support the large file kernel only starting with 7.0.  Note
that the compiler(s) provided with RedHat 7.0 - 7.2 are not
acceptable.  See the AIPS www page:

     http://www.aoc.nrao.edu/aips


 > florea> FRING1: ZCREA2: BYTES OVERFLOW ? = -1691384832

       This shows that the request for > 2 Gbytes is being handled in
a 32-bit integer and so it overflows and a negative arises.  The file
size is computed in a special 64-bit integer when properly compiled on
the latest systems.

 > florea> FRING1: INSUFFICIENT SPACE ON DISK  3 FOR FILE DA03:SCD007001.1PM;
 > florea> FRING1: REQUESTED SIZE OF     2542561 BLOCKS FROM ZCREAT
 > florea> FRING1: SCREAT: NO ROOM ON  3 FOR SCRATCH SIZE   2542561 KILOBYTES

The no room is just a guess at what the error means - the first line
is the real error.

 > AIPS seems to be having trouble coping with this very large disk.
 > Can you tell me how to work around this problem?
 > 

Properly compiled on systems recent enough it works fine.

Eric Greisen