Is My (and Yours) External HHD Failing?

[Cayenne1]

I'm getting conflicting results from examining the S.M.A.R.T. data from one of my external drives; a WD My Book 6 TB HHD w/24,000 hours.

Specifically, running the free Terminal based app "sysmontools" reports:

"SMART overall-health self-assessment test result: PASSED"

However, the commercial DiskRX reports for the same disk:

"Advanced S.M.A.R.T. Status: FAILING"

Both apps report the same for these values:

197 Current_Pending_Sector_Count: 704
198 Offline_Uncorrectable_Sector_Count: 272

DiskRX is very unhappy with these values as is a Google search. I have no idea what these items represent, but it was highly recommended to copy all files to another drive as it could go belly-up soon.

So with copying accomplished (a real PITA across available space) the question remained: "Should I Pitch the Drive?" These darn things are expensive and I have many TB of photos and videos. Far too many to rent cloud space.

At least my other drives checked out OK even with over 60,000 hours. If you've read this far it might be a good idea to check your external HHDs. Apple Disk Utility First Aid does NOT check hardware S.M.A.R.T. data, only file structure.

SSDs are a different matter as the technology and monitoring are completely different.

 

[GregoryPeckEPA]

I think you mean smartmontools.

SMART is a horrendous marker for hard drive health and integrity, especially when it comes to signs of imminent failure, in that, it won't catch 99% of HD failures. If SMART status reports imminent failure, your drive is on its last leg. Get your data off ASAP and prepare for file corruption.

Incidentally, macOS and SMART have a pretty tortured relationship. If you open Disk Utility and pull up info about your main storage device, it will say SMART status not supported. Going to System Information > Storage and you will say the same drive has a verified SMART status.

Additionally, there is a utility called Trash Me 3 that reveals Apple added a health sensor to its storage devices. This is from an M1 Mac Studio:

I reached out to the dev inquiring whether the health status reported was something unique to their app or something they got directly from the OS. The dev confirmed that it is reported by macOS itself!

I know this no longer applies as storage prices are lunacy right now, but I have never found losing data worth the few hundred for a new drive. If I were you, I would be trying to find an app that can both backup your data and verify its integrity. I had a 2TB HDD way back in the day die on me and before it stopped working completely, SMART reported failing but also the larger files, like movies, on the drive had a litany of garbled frames. I thought it was Subler (the app I used to convert all the mkvs to mp4s) but it turns out it was the drive itself.

Good luck!