I have a iMac (Late 2013) which has a standard 1TB 7200 RPM hard drive. Long story short, I noticed a dramatic slowdown in Windows (in Bootcamp) and on the Mac. After installing DriveDx, it reported that I had around 8,600 Reported Uncorrectable Errors. To my knowledge, that essentially means bad blocks/sectors.
After looking at this post, I followed the
fsck_hfs commands. I actually checked for bad blocks first using the
/sbin/fsck_hfs -S /dev/disk0s2 and then ran the
/sbin/fsck_hfs -drfy /dev/disk0s2 command.
After running the check Debug, Repair, Force command five times, all it would return is "The volume was modified" which to my research says that it is not complete, and that you should run it again.
A couple of questions. Does this command actually do anything to fix bad blocks? And if not, is there another command to actually fix the problem?