This is a kernel driver for Mac OS X external USB or FireWire drives. It extends the standard driver behaviour by providing access to drive SMART data. The interface to SMART data is same as with ATA family driver, so most existing applications should work.

The driver requires a SAT (SCSI ATA Translation) capable external drive enclosure. Check smartmontools list for supported devices: http://smartmontools.org/wiki/Supported_USB-Devices If the Option column contains sat or jmicron, the driver should work. The driver should work with Snow Leopard and Lion and Mountain Lion. People have reported problems with Lion and Encrypted volumes. Some enclosures are reported to work with FireWire but not with USB. The driver is not compatible to WD Drive Manager, or enclosures with custom kernel extensions.

• Unmount external drives
• Use the dmg image and the installer from Releases
• Check DiskUtility. The disks should have "S.M.A.R.T. Status: Verified"

Apple now wants us to sign drivers and extorts a very high fee for it. Now there's no chance we will be paying for it, so disable the check if you can.

On Yosemite, use:

sudo nvram boot-args-"kext-dev-mode-1"

On newer macOS, try (must be run in Recovery OS):

csrutil enable --without kext

If you are using OpenCore, you can move the kext file from its standard install location (/Library/Extensions/) to the EFI OpenCore directory and load it the OC way by editing the config file, config.plist.

The .plugin file should be left in the standard location.

• Remove driver and plugin

  sudo rm -r /System/Library/Extensions/SatSmartDriver.kext
  sudo rm -r /System/Library/Extensions/SatSmartLib.plugin
  sudo rm -r /Library/Extensions/SatSmartDriver.kext
  sudo rm -r /Library/Extensions/SatSmartLib.plugin
  

• Reboot

This driver creates a pretend ATA device over USB or FireWire. As a result, smartctl will not be able to use the -d sat option to access the device; instead, it will use the -d ata option.

You will also not be able to use smartctl's USB device database to decide which protocol to use. Instead, the driver will choose a protocol according to its own database, SatSmartDriver.kext/Contents/Info.plist. Because plists are plists, the USB IDs are stored in decimal, not the usual hexadecimal. This database is quite outdated and I hope to find a way to generate it automatically from the smartmontools database.

smartctl should remain able to detect the model and use model-appropriate interpretations of raw SMART values.

The .plugin file is required for smartctl, which calls on the plugin interface to connect.

• Compile all targets

  make pkg
  

• Unmount all existing external drives.

• Load the kernel extension.

  sudo tail -f /private/var/log/kernel.log &
  sudo make install
  

• The external drives should mount automatically.

• Test

  cd SatSmartDriver/build/Debug/
  ./smart_status
  ./smart_sample -a
  

• Check DiskUtility. The disk should have "S.M.A.R.T. Status: Verified"

• Install the driver to system permanently sudo make realinstall

• Reboot

• If you want to limit the driver for certain hardware add product and vendor identification to SatSmartDriver/Info.plist. Check chapter "Adding enclosure identification"

Check, if the enclosure is identified using shell:

ioreg -r -w 0 -c fi_dungeon_driver_IOSatDriver  | egrep 'Enclosure|PassThroughMode|Capable'| grep -v Identifiers
  |   "Enclosure Name" - "Unknown 0928:000a"
  |   "SatSmartCapable" - Yes
  |   "PassThroughMode" - "sat16"

Add an issue to GitHub.

Not possible in this driver, ever. Someone can write a pretend-NVMe driver some day.

(On a normal system, smartctl should handle all of this with an SCSI passthrough API. macOS is not a normal system so you can't go around shooting SCSI commands from userspace. Code duplication, yay!)

The code is based on Apple opensource files and is therefore published under Apple Public Source License. For details see http://www.opensource.apple.com/license/apsl/