sub get_size {
 my $disk=$_[0];
 my $size;
 eval {
  local $SIG{ALRM} = sub {
   print_debug("get_size timed out for device $disk");
   die;
  };
  alarm(4);
  $size=qx(bootinfo -s $disk 2>/dev/null);
  alarm(0);
 };
 $size=($size)? $size : "unknown";
 chomp $size;
 return $size;
}