very long boot sshd

[RazorOnFreeBSD]

I don't think sendmail is the problem... I disabled it from rc.conf... I
might be wrong but here is what I found in the /var/log/messages that could
be the suspicious :

kernel: ad2: UDMA ICRC error cmd=read fsbn 145503 of 14550 #Twice
kernel: ad2: UDMA ICRC error cmd=read fsbn 147135 of 14550 #4 times

and then :

262 falling back to PIO mode

The weirdest thing is that numbers seem to randomize a little bit.
If we consider the previous outputs like ...... fsbn A of B
A and B are different each reboot !

I don't know if it's the reason of very slow booting but I didn't find
anything about sendmail in /var/log/messages.......

Do you think I need to change my hardrive already ? It is just one year
..... :(