I assume any number of people here have used the hard drive analysis tool Spinrite. I have been trying to leave it to run a surface analysis while I'm off at work, because it takes hours. Apparently my entire workday plus commute still isn't enough: when I got home after 10 hours or so, Spinrite was only about forty percent done. I then noticed it says (if I understand correctly) I can start the analysis again later from the same percentage point I stopped at. But I can't figure out how to.

Back in the days of MFM and RLL Spinrite seemed a neat trick but once IDE drives evolved and especially SATA it became snake oil. It's basically a low-level formatter and modern drives not only don't need it, some can be damaged by it. Mr. Gibson received mucho flack over his assertion that drives needed "refreshing" to keep all the bits clean and clear. One major problem is returning bits back to service that the drive has marked bad and since ignored because the drive makes such a choice from repeated errors. Drives are now "wiser" (and more specific) than Spinrite. I do hate to bust ur bubble, but it really is time to retire Spinrite.

Noted, but that does not answer my question. I see this quite frequently on LQ: the only response or contribution to the question is "using that device or software is a waste of time; get something else."

You might have considered sending me a private message, for this comment that is relevant but not relevant at the same time.

And I don't know offhand what MFM and RLL are. Looking them up.

Yet enorbet did much more than that; gave you a full explanation. If you feel that didn't answer your question, then all hope is lost.
Thanks enorbet.

Here's the OP for future reference:

Regarding resuming spinrite, if you choose to use despite the above: https://superuser.com/questions/1543...inrite-session

Me, I've never had any interest in spinrite. And never will.

Thanks, that told me what I needed to know.