Oct 31 08:05:04 merk kernel: res
41/40:00:af:3a:d7/30:00:1e:00:00/00 Emask 0x409 (media error) <F>
Oct 31 08:05:04 merk kernel: ata1.00: status: { DRDY ERR }
Oct 31 08:05:04 merk kernel: ata1.00: error: { UNC }
That is the drive reporting a bad block yes. Whether it is a one off
failure or the start of a pattern of fails ending in doom is
unfortunately rather harder to tell.
Alan