Dear all,
I run PISCES using v4.0.6 with XIOS 2.5. The configuration has 797 procs (jpni x jpnj = 32 x 52) and the output fields look correct. However, I get the following message in the out.log file:
info : If domain grid_T does not have overlapped regions between processes something must be wrong with mask index.
Do I need to change anything in the set up based on this message?
I found a relevant ticket
http://forge.ipsl.jussieu.fr/nemo/discussion/topic/64
and I think that the message: info : If domain grid_T does not have overlapped regions between processes something must be wrong with mask index shows up because in my configuration jpni x jpnj > jpnij (exclude land). When I try e.g. (60 x 10 =600), this info does not appear.
I wonder how I could avoid this message by keeping the domain decomposition (32x52=797).
Does this message cause a real problem for my run?
I think you donāt really careā¦
I got (approximately) the same with NEMO v4.0.2, but my output files are corrects.
-> info : If domain grid_W does not have overlapped regions between processes something must be wrong with area index
Some friends told me that my French-English response was not really āappropriateā for non-french peopleā¦ Sorry for that. 
I just wanted to say that you should not worry about these warning messages.
XIOS warns you of the absence of data in regions corresponding to suppressed land processors but this is something expected in this case.