Hello again, following up from the mkudffs issues message i posted yesterday.. Looking at the mkudffs source, i found that the application (mkudffs) prints out an error message, and exits without further information when the blocks > start_ext->blocks.. do you have an explanation of what actually happens here, Ben? :) I'm getting this error each time i try to run the mkudffs app through a 'system' function call from a C++ program. Another thing, is that the code looks like this: if (start == start_ext->start) { if (blocks == start_ext->blocks) { ... } else /* blocks > start_ext->blocks */ { printf("trying to change type of multiple extents\n"); exit(1); start_ext->space_type = type; return start_ext; } ..... The statements after the exit(1) are never reached.... why are they there? Thanks, gustavo