In previous Solaris releases, you could not install and boot the Solaris OS from a disk that was greater than 1 terabyte in size. Starting with the Solaris 10 10/09 release, you can install and boot the Solaris OS from a disk that is up to 2 TB in size.
Starting with the Solaris 10 10/09 release, you can use the VTOC label on a disk of any size, but the addressable space by the VTOC is limited to 2 TB. This feature allows disks that are larger than 2 TB to be used as boot drives, but the usable space from the label is limited to 2 TB.
This feature is only available on systems that run a 64-bit kernel. A minimum of 1 GB of memory is required for x86 based systems.
For detailed information, see Two-Terabyte Disk Support for Installing and Booting the Solaris OS in System Administration Guide: Devices and File Systems.