Sim, consulte Como criar um pool raiz espelhado (pós-instalação) .
Apply boot blocks to the second disk after resilvering is complete.
sparc# installboot -F zfs /usr/platform/'uname -i'/lib/fs/zfs/bootblk /dev/rdsk/c1t1d0s0 x86# installgrub /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1t1d0s0
Verify that you can boot successfully from the second disk.