A:ZFS is the default root file system.

UFS is a supported legacy file system, but it is not supported as a bootable root file system.

E:

If your system has more than one OS installed on the system or more than one root boot environment in a ZFS root pool, you can boot from these boot environments for both SPARC and x86 platforms:

*Starting with the Solaris 10 10/08 release for a SPARC based system, you can boot a ZFS root file system in a ZFS pool. For ZFS root pools, you can list the available boot environments withthe boot command with the -L option. You can then choose a boot environment and use the OBP boot command with the -Z option to boot that boot environment.

*Starting with the Solaris 10 1/06 release for x86 based systems, a GRUB boot menu provides the interface for booting between different boot environments.

Note:

*The name originally stood for "Zettabyte File System"but today does not stand for anything.

Incorrect:

Not C: Mirroring is not enabled by default.

Not D:Alternate bootenvironments

If you want to create a backup of an existing boot environment, for example, prior to modifying the original boot environment, you can use the beadm command to create and mount a new boot environment that is a clone of your active boot environment. This clone is listed as an alternate boot environment in the GRUB menu for x86 systems or in the boot menu for SPARC systems.