[lustre-discuss] Odd behavior with Matlab.

[Laifer, Roland (SCC)]

Hello Phill,

we had the same problem. The reason is a Lustre bug and a odd way how
Matlab creates directories. This is all clearly described in
https://jira.hpdd.intel.com/browse/LU-4185

New Matlab versions just try to create all directories in the path and
they continue if the return code is EEXIST. Lustre *sometimes* provides
the wrong return code (EPERM instead of EEXIST). This is also described
in the update from 15/Feb/16 9:31 PM in LU-4185. Other applications
possibly have the same problem, too.

The good news is that future versions of Lustre will allow to change the
default behaviour (if I understood the last update correctly). It seems
that it is not planned to fix the bug as default since this would have a
performance impact. The bad news is that it will probably take some time
before the patch is available in stable Lustre versions. (I opened a
case and asked our Lustre support to provide the patch in their Lustre
version.) Also bad news is that Mathworks is not willing to provide a
workaround (we asked them, too).

Regards,
  Roland


Am 02.06.2016 um 11:04 schrieb Phill Harvey-Smith:
> Hi all,
> 
> I have recently compiled the lustre clients on Ubuntu 16.04, with help
> from this list I managed to get that working with source checked out on
> May 31.
> 
> In our environment we have the user's home directories on a lustre volume.
> 
> However when a user starts Matlab they have problems :
> 
> R2016a just dumps them straight back to a command prompt with the error:
> 
> Warning: failed to create preference directory /home/stsxab/.matlab/R2016a.
> 
> R2015a
> Starts up, displays the splash screen and then a big page of java
> errors, the first of which is :
> Internal error: No write permission on
> /home/stsxab/.matlab/R2015a/temp0x3e20x407d
> 
> R2014b
> Works as expected.
> 
> When I login with a user who's home directory is on the local
> filesystem, all 3 versions work correctly, which suggests a problem with
> the interaction between Lustre & Matlab.
> 
> Does anyone know how to fix this?
> 
> Cheers.
> 
> Phill.
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