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SUNLABEL(8)               BSD System Manager's Manual              SUNLABEL(8)

     sunlabel -- read or modify a SunOS disk label

     sunlabel [-mnqs] device

     sunlabel reads or modifies a SunOS disk label on device, which is used by
     the PROM on NetBSD/sparc hardware to find partitions to boot from.
     sunlabel only reads/writes the first 512 bytes of device.

     The supported options are:

           -m    Ignore an incorrect magic number in the disk label.

           -n    Synthesize a new label rather than reading what is there.

           -q    Quiet mode - don't print unnecessary babble (currently this
                 suppresses the ``sunlabel>'' prompt).

           -s    Ignore checksum errors when reading the label.

     Note that -m is dangerous, especially when combined with -s, since it
     will then happily believe whatever garbage it may find in the label.
     When using these flags, all values should be checked carefully, both
     those printed by L and the partition table printed by P.

     sunlabel prints a prompt ``sunlabel>'' and expects commands.  The follow-
     ing commands are understood:

           ?                 Show a short help message.

           [abcdefghijklmnop] <cylno> <size>
                             Change partition (see below).

           L                 Print label, except for the partition table.

           P                 Print the partition table.

           Q                 Quit program (error if no write since last

           Q!                Quit program (unconditionally) [EOF also quits].

           S                 Set label in the kernel (orthogonal to W).

           V <name> <value>  Change a non-partition label value.

           W                 Write (possibly modified) label out.

     The a through p commands will accept, for the <size> parameter, the
     nnn/nnn/nnn syntax used by SunOS 4.x format.  (For those not familiar
     with this syntax, a/b/c means a cylinders + b tracks + c sectors.  For
     example, if the disk has 16 tracks of 32 sectors, 3/4/5 means
     (3*16*32)+(4*32)+5=1669.  This calculation always uses the nsect and
     ntrack values as printed by the L command; in particular, if they are
     zero (which they will initially be if -n is used), this syntax is not
     very useful.  Some additional strings are accepted.  For the <cylno>
     parameter, ``end-X'' (where X is a partition letter) indicates that the
     partition should start with the first free cylinder after partition X;
     ``start-X'' indicates that the partition should start at the same place
     as partition X.  For the <size> parameter, ``end-X'' indicates that the
     partition should end at the same place as partition X (even if partition
     X ends partway through a cylinder); ``start-X'' indicates that the parti-
     tion should end with the last cylinder before partition X; and ``size-X''
     means that the partition's size should exactly match partition X's size.

     Note that sunlabel supports 16 partitions.  SunOS supports only 8.
     Labels written by sunlabel, when partitions i through p are all set
     offset=0 size=0, are identical to Sun labels.  If any of the ``extended''
     partitions are nontrivial, information about them is tucked into some
     otherwise unused space in the Sun label format.

     The V command changes fields printed by the L command.  For example, if
     the L command prints

           ascii: ST15230N cyl 5657 alt 2 hd 19 sec 78
           rpm: 0          pcyl: 0         apc: 0          obs1: 0
           obs2: 0         intrlv: 1       ncyl: 5657      acyl: 0
           nhead: 19       nsect: 78       obs3: 0         obs4: 0

     then V ncyl 6204 would set the ncyl value to 6204, or V ascii Seagate
     ST15230N cyl 5657 hd 19 sec varying would set the ascii-label string to
     that string.  sunlabel performs very few consistency checks on the values
     you supply, and the ones it does perform never generate errors, only

     der Mouse <mouseATrodents.ca>

     It may be that the space in the label where the information for the
     extended partitions is saved is used by SunOS.

     Not very many consistency checks are done on the V arguments, and those
     only produce warnings.

     NetBSD doesn't support 16 partitions in a Sun disk label yet.

BSD                            December 21, 2002                           BSD