I was wondering if anyone knows what the following kernel error message may
mean :

/netbsd: wd2f: obsolete (address mark not found) reading fsbn 505826 (wd2 bn
505889; cn 501 tn 13 sn 62)

A scan through the raw partition reveals a single sector error (512B) at
that location, and it is sitting under one of the data blocks of a file. Now
I have seen "uncorrectable data error reading" and "device timeout reading",
and  "id not found reading" before, but this is a new one for me.

Thanks
  Stuart