To pad a vector, i.e., copy a vector to a new one, I have to call VecSetValue(newb,1,&idx,...) for each element. But to be efficient, what I really needs is to set a block of values in one call. It looks PETSc does not have a routine for that(?). I looked at VecSetValuesBlocked, but it looks it is not for that purpose. Should we have something like VecSetValuesBlock(Vec <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/Vec.html#Vec> v,PetscInt <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Sys/PetscInt.html#PetscInt> i,PetscInt cnt,PetscScalar <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Sys/PetscScalar.html#PetscScalar> *value, InsertMode <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Sys/InsertMode.html#InsertMode> mode) to set cnt values starting at index i? --Junchao Zhang