Question on migrating data between PVs in xfs

[Wei Lin]

Hi Dave,

Now I see your point. Initially I wanted to store the linear concat
layout in a special file, read this file during allocation to compute on
the fly if an extent falls into a physical volume. But now I do agree
that from the perspective of OS engineering, filesystems should not know
the underlying layout, at least not in such an "ad-hoc" way. Aligning
AGs to physical volumes and applying allocation policy might be the best
approach.

Thank you very much for the help.

Cheers,
-- 
Wei Lin