offset=$((offset - $CHUNK_SIZE * 2))
while [ $offset -ge 0 ]; do
$XFS_IO_PROG -c "fpunch $offset $CHUNK_SIZE" $SCRATCH_MNT/spc \
offset=$((offset - $CHUNK_SIZE * 2))
while [ $offset -ge 0 ]; do
$XFS_IO_PROG -c "fpunch $offset $CHUNK_SIZE" $SCRATCH_MNT/spc \