Solaris 10 10/09: In previous releases, you could not install and boot the Solaris OS from a disk that was greater than 1 Tbyte in size. Starting with this release, you can install and boot the Oracle Solaris OS from a disk that is up to 2 Tbytes in size. In previous releases, you also had to use an EFI label for a disk that was larger than 1 Tbyte. In this release, you can use the VTOC label on any size disk. However, the addressable space by the VTOC label is limited to 2 Tbytes.
For more information, see What’s New in Disk Management? in System Administration Guide: Devices and File Systems.