After three months without a second hard disk, a new fresh one came from the manufacturer. Just scheduled a little intervention-time window; the main server is back online in less than fifteen minutes.
I just hope that this one will have a little more longer life than the past disk.
As a side note, i just have to remove the old
and insert the second disk in it, again:
# gmirror forget gm0 # gmirror insert gm0 ad10 # gmirror status Name Status Components mirror/gm0 DEGRADED ad8 ad10 (16%)