stock: total=1073725440 bbase=4096 pbase=1032192 pstop=1072676864 nparts=16
control: write at slice offset 0 with stock label
  pwrite(/dev/vn0s1, off 0) = -1 errno=30 (Read-only file system)
installed label with d_bbase=0 (accepted)
  pwrite(/dev/vn0s1, off 0) = 512 errno=0 (WRITE ACCEPTED BELOW LABEL)
after-bbase0: total=1073725440 bbase=0 pbase=1032192 pstop=1072676864 nparts=16
installed label with d_bbase=1072676864 (accepted, unvalidated)
  pwrite(/dev/vn0s1, off 0) = -1 errno=30 (Read-only file system)