My internal hard drive was playing up and diagnostics found that it had 20 bad sectors. I've since done a high security erase of the drive and all my issues seemed to go away. Disk Utility reported the drive was okay and I was able to reinstall OS X and restore from a TM backup, etc.

However, a few 3rd party apps indicate my drive now has 21 reallocated bad sectors. I imagine this is better than the previously reported 20 bad sectors (now showing as 0), but these apps are indicating my drive is still failing solely due to that.

I haven't been able to find much information on the web about lifetime of a drive after having reallocated bad sectors, so I'm unsure of what to do. Will these reallocated bad sectors become a problem, or are they indicative that the problems haven't stopped? Should I bite the bullet and just install a new SSD?

  • I agree with the answer. These are symptoms of a failing drive – n1000 Feb 23 '17 at 10:20
  • When you mark sectors as bad, the drive controller knows not to use them and reports "everything's fine" to the OS. This is from the old MFM and RLL drives of yesteryear that came from the factory with bad sectors. This is no longer the case. But a failing drive whether MFM/RLL or the new SATA will continue to develop failures - you need to get it replaced. – Allan Feb 23 '17 at 11:13

This question could be considered 'opinion-based' however, in my opinion...

No hard drive is ever going to 'heal' over time; it can only degrade.
If it's developed bad blocks before, it will likely develop more as time goes on.

Unless you have a Time Machine constantly connected & working, giving you an hourly safety-net, I'd bit the bullet & swap it out now.

Better safe than sorry.

You'll also love the speed the SSD gives you. It will feel like a new machine... or actually faster than new.

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