Mirror Disk fault..

# gpart create -s GPT ada

# gpart backup ada0

# gpart backup ada0 | gpart restore -F ada1

# zpool online zroot ada1

# zpool replace zroot ada

root@www: # zpool status
pool: zroot
state: DEGRADED
scan: resilvered 23.4G in 00:07:00 with 0 errors on Sat Sep 4 20:36:03 2021
config:

    NAME        STATE     READ WRITE CKSUM
    zroot       ONLINE       0     0     0
      mirror-0  ONLINE       0     0     0
        ada0p3  ONLINE       0     0     0
        ada1p3  OFFLINE      0     0     0
      mirror-1  ONLINE       0     0     0
        ada2p3  ONLINE       0     0     0
        ada3p3  ONLINE       0     0     0