zfs replace disk has failed

[Dan Cojocar]

Hello all,
In a mirror(ad1,ad2) configuration one of my disk(ad1) had failed,
after replacing the failed disk with a new one using:
  zpool replace tank ad1
I have noticed that the replace is taking too long and that the system
is not responding,  after restart the new disk was not recognized any
more in bios :(, I have tested also in another box and the disk was
not recognized there too.
I have installed a new one on the same location (ad1 I think). Then
the zpool status has reported something like this (this is from memory
because I have made many changes back then, I don't remember exactly
if the online disk was ad1 or ad2):

zpool status
  pool: tank
 state: DEGRADED
 scrub: none requested
config:

        NAME                        STATE     READ WRITE CKSUM
        tank                        DEGRADED     0     0     0
          mirror                    DEGRADED     0     0     0
            replacing               UNAVAIL      0   387     0
insufficient replicas
              10193841952954445329  REMOVED      0     0     0  was /dev/ad1/old
              9318348042598806923   FAULTED      0     0     0  was /dev/ad1
            ad2                     ONLINE       0     0     0
At this stage I was thinking that if I will attach the new disk (ad1)
to the mirror I will get sufficient replicas to detach
9318348042598806923 (this one was the disk that has failed  the second
time), so I did an attach, after the resilvering process has completed
with success, I had:
zpool status
  pool: tank
 state: DEGRADED
 scrub: none requested
config:

        NAME                        STATE     READ WRITE CKSUM
        tank                        DEGRADED     0     0     0
          mirror                    DEGRADED     0     0     0
            replacing               UNAVAIL      0   387     0
insufficient replicas
              10193841952954445329  REMOVED      0     0     0  was /dev/ad1/old
              9318348042598806923   FAULTED      0     0     0  was /dev/ad1
            ad2                     ONLINE       0     0     0
            ad1                     ONLINE       0     0     0
And I'm not able to detach 9318348042598806923 :(, and another bad
news is that if I try to access something under /tank the operation is
hanging, eg: if I do a ls /tank is freezing and if I do in another
console: zpool status which was working before ls, now it's freezing
too.
What should I do next?
Thanks,
Dan