SUNLABEL(8) BSD System Manager's Manual SUNLABEL(8)NAMEsunlabel — read or modify a SunOS disk label
SYNOPSISsunlabel [-mnqs] device
DESCRIPTIONsunlabel 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 following
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
change).
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 parti‐
tion should end at the same place as partition X (even if partition X
ends partway through a cylinder); “start-X” indicates that the partition
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
warnings.
AUTHORS
der Mouse ⟨mouse@rodents.montreal.qc.ca⟩
BUGS
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
