SOLARIS 10 ZFS, I want to add spare with rpool but it gives me this error "cannot label 'c1t4d0': EFI labeled devices are not supported on root pools"

Question

#zpool status
  pool: rpool
 state: ONLINE
 scan: resilvered 8.09G in 0h2m with 0 errors on Wed Sep 21 14:10:40 2022
config:

        NAME          STATE     READ WRITE CKSUM
        rpool         ONLINE       0     0     0
          mirror-0    ONLINE       0     0     0
            c1t0d0s0  ONLINE       0     0     0
            c1t1d0s0  ONLINE       0     0     0

errors: No known data errors

  pool: xpool
 state: ONLINE
 scan: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        xpool       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            c1t2d0  ONLINE       0     0     0
            c1t3d0  ONLINE       0     0     0

errors: No known data errors

---

#zpool add -f rpool spare c1t4d0
cannot label 'c1t4d0': EFI labeled devices are not supported on root pools.

Answer 1

You can change the EFI label with command:

# format -e c1t4d0
.
.
.
format> label
[0] SMI Label
[1] EFI Label
Specify Label type[1]: 0
Auto configuration via format.dat[no]?
Auto configuration via generic SCSI-2[no]?

and try again