Hard drive device name on Solaris

/dev/rdsk/c0t0d0s0 means Controller 0, SCSI target (ID) 0, and s means Slice (partition) 0.

Typically, by convention, s2 is the entire disk. This partition overlaps with the other partitions.

prtvtoc /dev/rdsk/c0t0d0s0 will show you the partition table for the disk, to make sure.

If you run Solaris on non SPARC hardware and don't use EFI, the whole hard drive is not c0t0d0s2 but c0t0d0p0, s2 is in that case just the Solaris primary partition.

What do you want to do to the whole disk? Look at the EXAMPLES section of the man page for the command in question to see how much of a disk name the command requires.

zpool doesn't require a partition, as in: c0t0d0 newfs does: c0t0d0s0 dd would use the whole disk partition: c0t0d0s2

Note: s2 as the entire disk is just a convention. A root user can use the Solaris format command and change the extent of any of the partitions.