Hello again,

Some time ago I have post a message to the list about the problem with the 
SIESTA (built on IBM Power system) running out of luns. The original post is 
below. In the meantime I have contacted the system administrator, who helped me 
to identify the problem. Here is his response:

this is an error message from SIESTA itself. You
can find it in the source file io.f after a check
of all fortran i/o units. The constants min_lun
and max_lun are set as 10 and 99 in the version
of the code that I have, which means that there
can be 89 files simultaneously open. There are
two possible solutions:
1. increase max_lun so that you can have more files
simultaneously open. However, my guess is that your
code opens a file at every step, but never closes it
and so it runs out of units after 81 or 82 steps. The preferred
solution is therefore
2. to look for the open files and close them at appropriate
points in the code.

As my fortran skills suck like anything, and the SIESTA source is rather big, I 
cannot do that myself. Moreover, it really seems like a bug to me, so I am 
hoping that the developers would be interested in sorting this out...

With regards,
Bartek


________________________________________
From: Szyja, B.M. [[email protected]]
Sent: Monday, March 29, 2010 11:27 AM
To: [email protected]
Subject: [SIESTA-L] error - No luns available in io_assign

Dear SIESTA Team,

I am trying to run MD simulations using SIESTA on IBM power architecture. 
Everything seems ok up to a moment when the jobs crash and I get the following 
error message:

No luns available in io_assign
Stopping Program from Node:    0

It usually happens after 70-80 succesful steps of MD. Does anybody have an idea 
what might be the cause?

Bartek

Responder a