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WAVECAR incompatibility among different machines...

Posted: Thu Nov 09, 2006 8:21 am
by lahaye
Hi,
I have four different machines at my disposal:

1. Pentium4 desktop (Fedora OS /w linux 2.6.18)
2. Pentium4 cluster (RedHat Enterprise Edition /w linux 2.4.21)
3. Compaq Alpha Server (CentOS 4.3 /w 2.6.9)
4. HP Itanium system (CentOS 4.3 /w linux 2.6.9)

Machines 1, 2 and 3 can share the WAVECAR, i.e. a job ended on
one machine can be continued on another machine.
However, the Itanium machine cannot do that; WAVECAR produced
there, produce on another system:

Code: Select all

nup: number of bands has changed, file:   0 present:   8
instead of

Code: Select all

the WAVECAR file was read sucessfully
The same problem when using a WAVECAR file from machines 1,2 or 3
on the Itanium machine.

This incompatibility is rather inconvenient. Is there a way to deal with this?

Thanks,
Rob.

WAVECAR incompatibility among different machines...

Posted: Thu Nov 09, 2006 1:52 pm
by tjf
You need a little tool to convert the binary representation used on the 32 bit machines to that used on the 64 bit machine. It'll need to be taylored to the specific structure of the WAVECAR file, so a general tool won't work. How to write such a tool depends on your compilers. I can't be much more help than that.

WAVECAR incompatibility among different machines...

Posted: Wed Nov 15, 2006 5:58 am
by lahaye
Tjf, thank you for your feedback.

I finally discovered what's the issue here. It turns out not to
be an 32-bit vs. 64-bit issue.

I used the prefabricated makefiles from VASP on the respective
systems to compile VASP. The trouble was caused by the
presence/absence of the "-assume byterecl" in the FFLAGS of
the corresponding systems. This difference made the unformated
binary datafiles incompatible.

Compiling vasp on all systems with "-assume byterecl", seems to
solve the problem.

I wonder why this compiler option is pressent in the makefile of
Intel-P4 and Alpha systems, but not of Itanium systems.

Regards,
Rob.