Inconsistent reporting S.M.A.R.T status for external SSDs

DriveDx does provide detailed SMART reporting for external drives but a kernel extension must first be installed (DriveDX provides a simple way to do this). Also Drive Scope (Micromat) provides similar SMART reporting on external drives but the same kernel extension must first be installed as well.

You can also do this yourself with a Knoppix utility and thumb boot drive without installing the above kernel extension. The only cost is the cost of the thumb drive. These instructions came from HWTech in previous posts and I have followed them so I know they do work:

"Download a Knoppix v8.6.1 DVD .iso image if it is still available, otherwise download the most recent version (I have not personally tried the v9.x version yet). Get one with "EN" in the name for "ENglish". Use the downloaded Knoppix .iso file as a source for Etcher (Mac/Windows/Linux) which will create a bootable USB stick. Option Boot the Knoppix USB stick and select the orange icon labeled "EFI". The Mac may appear frozen on the boot picker menu so give Knoppix lots of time to finish booting.

Once it boots to the Knoppix desktop click the "Start" menu button on the lower left corner of the Taskbar and navigate the menus to "System Tools ---> GSmartControl". Within the GSmartControl app double-click on the icon for the hard drive which will open the health report for the drive."

Bruce Michel wrote:

• Eight months ago I started using Crucial X8 1TB SSDs as the boot drive Macintosh SSD and as Time Machine on my late 2015 iMac via USB3 . Both have worked well.

I have wondered how to monitor the health of these drives. Crucial does not provide any utility for a Mac.

The support within Big Sur is confusing (also reported via Feedback):

System Information>Hardware>Storage provides no S.M.A.R.T information for the volumes on the SSDs. But it does give it for the unused Macintosh HD

• System Information>USB gives "Verified" for both

Not clear if the verified status really reflects timely monitoring or not.

Are there any apps that would provide this information similar to DriveDx?

SMART is not a very reliable parameter.

and why not DriveDX...? it does take some experience interpreting the result

https://binaryfruit.com/drivedx

to verify the health of the hard drive.

If you value your user data:

3-2-1 Backup Strategy: three copies of your data, two different methods, and one offsite.

If you are trying to access the SMART information from a USB drive, then the USB controller for the USB Adapter, drive dock, or enclosure must allow the SMART communication to pass from the OS/app to the physical drive, but unfortunately many USB controllers on the adapters/docks/enclosures don't allow this to happen.

Plus with an NVMe based SSD, it may not support the traditional SMART interface to access the SMART information on the SSD. While some NVMe SSDs may have the older style access, most NVMe SSDs now have a new method of accessing the SSD's SMART health information. On Linux, this requires using a special new NVMe utility to access an NVMe SSD's SMART information and as far as I know can only be done through the command line. The only way to possibly check the health of the external NVMe SSD may be by using a Linux system or boot disk as suggested, but the GSmartControl app may not work for this purpose as it may require using the "nvme" command line utility which can be a bit tricky to use. If you are familiar with the command line, then I can give you some hints on how to attempt to check the NVMe USB SSD's health using Linux, but it may require you to do a little thinking & interpreting to actually identify the correct drive identifier for the SSD you want to check.

macOS has never really supported using SMART health information except to alert the user if a drive has a SMART health attribute reach a failure state which is quite rare since a hard drive rarely makes it that far before the drive issues make it impossible to boot the computer (I've only seen it happen two or three times on macOS, but I've replaced hundreds of bad hard drives that never had an macOS SMART alert issued). Sometimes the Apple Diagnostics may check the SMART attributes/health, but not to the necessary level of detail needed to catch most drive failures. It is unfortunate operating systems and drive vendors and even the makers of adapters/docks/enclosures do not properly implement or allow for access to a drive's SMART health information.

The "verified" you see on USB drives is meaningless because macOS does not support SMART status over USB without third party driver.