Seagate disk ST340824A is detected as a 5.77GB disk, it should be approximately
40GB.

# format
AVAILABLE DISK SELECTIONS:
    0. c0t0d0 <ST340824A cyl 19156 alt 2 hd 15 sec 255>
       /pci@1f,0/ide@d/dad@0,0
    1. c0t2d0 <ST340824A cyl 12007 alt 2 hd 16 sec 63>
       /pci@1f,0/ide@d/dad@2,0

The above is an example of a disk (c0t0d0) showing the correct size and a disk
(c0t2d0) showing an incorrect size.            

Using the Solaris (TM) Operating Environment format utility, select the problem disk -> type -> other. Then change the disk geometry to the following:

Cyl -> 19156 Alt -> 2 Hd -> 16 Sec -> 255

The steps to change the disk geometry follow:

# format

Searching for disks...done

AVAILABLE DISK SELECTIONS:

0. c0t0d0 <ST340824A cyl 19156 alt 2 hd 15 sec 255>

/pci@1f,0/ide@d/dad@0,0

1. c0t2d0 <ST340824A cyl 12007 alt 2 hd 16 sec 63>

/pci@1f,0/ide@d/dad@2,0

Specify disk (enter its number): 1

selecting c0t2d0

[disk formatted]

FORMAT MENU:

disk - select a disk

type - select (define) a disk type

partition - select (define) a partition table

current - describe the current disk

format - format and analyze the disk

repair - repair a defective sector

label - write label to the disk

analyze - surface analysis

defect - defect list management

backup - search for backup labels

verify - read and display labels

save - save new disk/partition definitions

inquiry - show vendor, product and revision

volname - set 8-character volume name

!<cmd> - execute <cmd>, then return

quit

format> type

AVAILABLE DRIVE TYPES:

     0. Auto Configure
     1. Seagate ST340824A
     2. Other
Specify disk type (enter its number)[1]: 2
Enter number of data cylinders: 19156
Enter number of alternate cylinders[2]: 
Enter number of physical cylinders[1868]: 
Enter number of heads: 16
Enter physical number of heads[default]: 
Enter number of data sectors/track: 255
Enter number of physical sectors/track[default]: 
Enter rpm of drive[default]: 
Enter format time[default]:

  < accept default to all remaining questions >

Enter disk type name (remember quotes): "Sun_40GB"
Selecting c0t0d0
format> quit                       

At this point the disk should be seen as a 40GB disk.