[petsc-users] Field split degree of freedom ordering

In the block matrices documentation, it's stated: "Note that for interlaced storage the number of rows/columns of each block must be the same size" Is interlacing defined in a global sense, or a process-local sense? So explicitly, if I don't want the same size restriction, do I need to ensure that globally all of my block 1 dofs are numbered after my block 0 dofs? Or do I need to follow that on a process-local level? Essentially in libMesh we always follow rank-major ordering. I'm asking whether for unequal row sizes, in order to split, would we need to strictly follow variable-major ordering (splitting here meaning splitting by variable)? Alex