zpool attach Might Create an Illegal Root Pool (6740164)

When you attach a device to a root pool to create a mirrored root pool, zpool attach might create an illegal root pool if a whole disk is added to the pool. A ZFS root pool must be created with disk slices, not whole disks. If you attempt to boot from the whole disk that was added to the mirrored root pool, the system will not boot.

Workaround: Perform the following steps:

1. Detach the disk from the pool. For example

   # zpool detach rpool c0t2d0

2. Change the disk label to a VTOC (SMI) label. For example:

   # format -e . . . Select disk c0t2d0 format> label [0] SMI Label [1] EFI Label Specify Label type[0]:0 Ready to label disk, continue? yes format> quit

3. Add a disk slice back to the pool to create a mirrored root pool. For example:

   # zpool attach rpool c0t2d0s0

See also zpool attach Command Does Not Copy bootblock Information (6668666).