If the GRUB 2 boot loader becomes corrupted, and the system can no longer boot, you might be required to boot from media and manually reinstall the boot loader. To reinstall the boot loader, you must boot from the Oracle Solaris installation media (for example, by using the text installer ISO image) and get to a command prompt.
You must import the root pool before you can reinstall GRUB 2. The following procedure describes the steps to follow.
# zpool import -f pool-name
# bootadm install-bootloader [-f] -P pool-name
Forces the installation of the boot loader an bypasses any versioning checks for not downgrading the version of the boot loader on the system.
Specifies the boot configuration for the pool to be used
# zpool export pool-name
On systems with BIOS firmware, sometimes it is necessary or desirable to install GRUB 2 into the master boot record. The following procedure describes how to do so. After the installation, GRUB 2 is then the default system boot loader, regardless of which DOS partition is marked as the active partition. When DOS partitioning is used on systems with BIOS firmware, and the Solaris partition is a primary partition, the default GRUB 2 installation location is the partition boot record. If the partition is a logical partition, GRUB 2 is always installed in the MBR.
# bootadm install-bootloader -M