Slice 2 on Solaris system

On sparc, s2 is the size of the entire disk. On the i86pc platform (i.e. x86 and x64), it is the size of the entire partition devoted to Solaris and Solaris's slices.

Never touch or modify slice 2. Ever. If you mess with s2, you could screw up your other slices, could screw up disk content. Worst of all, you could screw up the currently detected geometry settings, especially in those scenarios where s2 is the size of the entire disk.
 
s2 can be used to back up entire disks, or all slices devoted to Solaris simultaneously, where s2 doesn't occupy the entire disk. This is usually performed with the `dd` utility.