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Disk Utility reports the S.M.A.R.T. Status as not verified for external disks, and by default Mac OS X only seems able to access S.M.A.R.T. information on internal hard drives.

Is there a way to get SMART information on external USB or Firewire hard disk?

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Interestingly enough, Windows tools like CrystalDiskInfo can access SMART data over USB when running under VMWare Fusion. So technically you can access SMART on Mac OS X if you have VMWare with Windows. Hope this helps someone. – Dmitry Dec 18 '13 at 19:55
up vote 7 down vote accepted

Yes (maybe).

There's an open-source kernel driver OS-X-SAT-SMART-Driver for Mac OS X that will work for some USB and Firewire enclosures. It uses SAT (SCSI ATA Translation) to pass the SMART commands through to the hard drive, so only works if your enclosure supports SAT.

SAT isn't something enclosures seem to advertise support for, but the one I use (WD MyBook Studio Edition) happens to support it, so it works for me. It'll probably be quicker to test the software with your drive/enclosure, than to find out if SAT is supported in the specs.

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Although this may not be the only option to get the SMART status, as I could not retrieve the SMART status for a drive in an enclosure using a Sunplus Technology USB to SATA bridge in OS X - but from the same combination of HDD and enclosure I could successfully get the SMART data using Windows XP (even in a virtual machine) and HDDScan (see Appendix A on that site for supported controller chips) – iolsmit Jul 31 '12 at 21:21
The Sharkoon SATA Quickdeck Pro doesn't seem to support SAT. Tested with OS-X-SAT-SMART-Driver version 0.6. Three different external hard disk enclosures (Toshiba DWC130 HDWC130EK3J1, Hitachi Touro DX3 DTOLDX1EB40001ABB, Gdrive GDRU3EA5001ADB) did support SAT. – Pro Backup Jul 24 '13 at 18:20
See… for a list of supported devices. – Pro Backup Jul 24 '13 at 19:00
@ProBackup The page you linked lists many different kinds of devices that are supported by smartmontools; is it just the ones that indicate options -d sat that are supported by the SAT SMART Driver? – rakslice Mar 17 '14 at 1:37
@rakslice When I re-read the "Supported devices" table, I would say yes only the USB drives with -d sat are supported via the SAT SMART driver. – Pro Backup Mar 17 '14 at 10:15

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