If you use the zpool attach command to add a disk to a ZFS root pool, the bootblock information is not copied to the newly added disk. This problem does not affect mirrored ZFS root pools that are created with an initial installation. System does not boot from alternate disk in the mirrored root pool.
Workaround: Choose one of the following workarounds:
On a SPARC system, identify the alternate disk device and install the boot information. For example:
# installboot -F zfs /usr/platform/`uname -i`/lib/fs/zfs/bootblk /dev/rdsk/c0t1d0s0 |
On an x86 system, identify the alternate disk device and install the boot information. For example:
# installgrub /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c0t1d0s0 |