Way to give your HDD some more life
One thing I looked into a lot on the net and found out myself, is what to do when you start getting some "bad sectors", a problem I came across with my HDD which recently caused boot failure just out of nowhere and received the "treatment" I explain.
1.Backup your data
2.Try to give your HDD an orientation. I mean, tell ALL its little magnetic parts (sorry I am not an engineer) to have the same polarity (seems they get a little crazy after some overwrites...) Best and easiest way to do that is by a zerofill, which makes your entire disk like 000000000000..., but there are also some Windows apps like DRevitalize that do pretty much something like that in not so uniform a way (and without losing data supposingly-never tried it to be honest)
You can do a zerofill by a slow format (device, not just partition) in Ubuntu's Disks GUI, or through your terminal, using the "shred" command: sudo shred -n 0 -v -z /dev/sdX (where sdX the disk you want to erase) and probably in a million other ways, I don't think it matters that much how you do it.
I tried a 2-pass zerofill on a disk with 250 bad sectors and 75 more "pending". It eliminated the "pending" sectors somehow and significantly improved access times for some 2500 more sectors, from "<500ms" to "<150ms" (surface test with HDDScan). I guess some of those would soon become "bad" and remains to see if I can expect a time gain of days, weeks or more...