Re: [Libmesh-users] how to read a distributed mesh

[Roy S. <roy...@ic...>]

On Mon, 4 Dec 2017, John Peterson wrote:

> On Mon, Dec 4, 2017 at 10:59 AM, Alam, Jahrul <al...@mu...> wrote:
>
>> Thanks for the clarification. Can you suggest a work around? If I do,
>> mesh0.read(lshaped_0.vtu) and mesh1.read(lshaped_1.vtu), and so on, is it
>> possible to end up with a DistributedMesh by combining mesh0,
>> mesh1,............. at the user level?
>>
>> Or, is there another format that supports parallel read and write?
>
> I wouldn't worry about parallel read/write until you get to a point that
> you are working with a Mesh that's too big to even be opened on one
> processor.
>
> Your code can still run in parallel even when you read a mesh in serial.

For the sake of completeness, I'll point out that you can read and
write distributed meshes in either the standard Nemesis format or in
a libMesh-specific (and libMesh-version-specific! beware!)
"Checkpoint" format.  (Our libMesh-specific XDR format let you write
solution data in parallel, but not mesh data currently)

I would definitely suggest taking John's advice, though.  For archival
purposes of final solutions, serialized mesh files are just easier to
deal with.  Parallel mesh files become useful when you have so much
data to write out (transient problem with a good solver with which you
want to make a movie?) that I/O becomes a bottleneck.
---
Roy