MM5 Model on ALPHA
Running larger jobs on ALPHA
Many users have experienced problem running 'big' jobs on either
single or multiple processor Alpha machines (big jobs mean that
one either has large dimensions for MIX, MJX and MKX, or many nests).
The typical error message is 'Segamentation fault', or
%DECthreads bugcheck (version V3.15-421), terminating execution.
% Reason: Failure initializing the manager thread tcb (12)
% Running on OSF1 V4.0 on , 768Mb; 1 CPUs
This is usually the indication that the job doesn't have enough
memory to run. However this doesn't always mean that your machine
doesn't have enough memory, most times, it means the machine isn't
configured to run large jobs.
There are several steps you can try to 'fix' the problem.
-
Type 'limit' on your machine and find out what you have. You
should see something like
cputime unlimited
filesize unlimited
datasize 1048576 kbytes
stacksize 65536 kbytes
coredumpsize 0 kbytes
memoryuse 56284 kbytes
vmemoryuse 1048576 kbytes
descriptors 200
-
If there are multiple processors on the machine, also try to
set environment variable MP_STACK_SIZE by typing
setenv MP_STACK_SIZE 96000000
-
Then type 'unlimit' and 'limit' again to see what you have.
You should probably see some changes in the numbers listed above.
Many times, this should help, and you may start to run MM5 job.
-
If you continue to have problem, and if you don't see the
numbers change much before and after you type 'unlimit', and
some numbers are small compared with the real memory you have
on your machine (for example, if you have 1 Gb memory on your
machine, and you don't see that displayed under the 'limit'
you may need to reconfigure your machine.
MM5 input and output data on DEC ALPHA
Since DEC Alpha uses an IEEE data format (which is called lillte
endian) that is different from most of worstations (which is referred
to as big endian), we have included the following
-convert big_endian
in the compile options for DEC (see the configure.user file)
in order for the model to use the same data as on other workstations.
However, including this compile option implies that the output from
MM5 on DEC is also in standard, big_endian IEEE format. Therefore
if you want to run any application programs that read the model
data, you would also need to include this compile option in your
compilation.
Compliing MM5 on DEC ALPHA
The following patch is required to run MM5 model on DEC ALPHA
with its new 4.1 Fortran compiler:
*FORTRAN-OSF]FORTAUE01041
(provided by Digital)
|