While searching around I stumbled on a post Seagate's Seek Error Rate, Raw Read Error Rate, and Hardware ECC Recovered SMART attributes. In this post, the author explains that all the values are actually 48 bits, and due to the way they are encoded it follows that those values are large. More specifically, raw value of the Seek error rate attribute should be converted to hexadecimal and then upper 16 bits are number of errors, while lower 32 bits are total number of seeks.
In this concrete case the raw value for Seek error rate is 17262017054, or 0x000404E57A1E. The first 16 bits is 0x0004 and the last 32 bits are 0x04E57A1E. What this means is that there were 4 seek errors (meaning the head wasn't positioned correctly after being moved to some track) but there were 82147870 seeks in total. So, this is very very small fraction of errors.
Ooooook. Sur un disque dur Seagate, une valeur positive pour l'attribut SMART « Raw Read Error Rate » ou pour l'attribut « Seek Error Rate » ne signifie pas forcément que le disque commence à aller mal…