Maybe it is due to the fact (https://www.smartmontools.org/wiki /Supported_USB-Devices) that USB connected disks usually need a '-d' option to enable S.M.A.R.T. support.
In fact, for the same disk, trying first: $ sudo smartctl -d scsi -H -i -A -l error -l selftest '/dev/sdb' gives "SMART support is: Unavailable - device lacks SMART capability.", whereas: $ sudo smartctl -d scsi -d sat -H -i -A -l error -l selftest '/dev/sdb' gives "SMART support is: Available - device has SMART capability.//SMART support is: Enabled", and the full output expected. And also in GSmartControl I have to add the "-d sat" option to Preferences/Drives to enable S.M.A.R.T. support and view attributes. The difficulty to include this in gnome-disk-utility is that each disk needs a different "-d" option... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1540110 Title: gnome-disk-utility (shown as "Disks") shows SMART option grayed for USB connect disks despite being available. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-disk-utility/+bug/1540110/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs