Recovering a failed GPT disk

• before hot replacing a disk, say ada5, run

# zpool offline zroot ada5

and check

# zpool status

• Insert a new physical disk
• Copy the partition table to the new disk from a healthy one
• Label all partitions with the commands:

# gpart modify -l LABEL -i1 ada5

• Fill the EFI partition:

#newfs_msdos -F 32 -c 1 /dev/ada5p1

# mount -t msdosfs /dev/ada5p1 /mnt

# mkdir -p /mnt/EFI/BOOT /mnt/EFI/FREEBSD

# cp /boot/loader.efi /mnt/EFI/BOOT/BOOTX64.efi

# cp /boot/loader.efi /mnt/EFI/FREEBSD/

# umount /mnt

• Fill the freebsd-boot partition:

#gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 2 ada5

• Check:

#loaders-update show-me

• Return ada5p3 to the ZFS pool:

#zpool replace zroot ada5p3