> On Jun 27, 2016, at 3:15 PM, Xiangdong <[email protected]> wrote:
> 
> Hello everyone,
> 
> I am trying different number of da_overlap to see its effects on nasm and 
> aspin preconditioner. The codes works fine with -da_overlap 0. However, when 
> I change the option -da_overlap 1, it crashed with the error message like 
> "zero pivot row 12544 value 0 tolerance 2.2e-14". The option 
> -pc_factor_nonzeros_along_diagonal does not fix this zero pivot issue.
> 
> Do you have any quick suggestions for me to try to fix this issue?

   My guess is that it is bug in the da_overlap business or in the example; 
normally I would not expect this to happen. Is this a PETSc example I can run 
(tell me example and exact options) to reproduce the problem?

   Thanks

   Barry

> 
> Thank you.
> 
> Best,
> Xiangdong

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