For more information about this issue, see https://askubuntu.com/a/1106020/50254
TL;DR: Linux kernel disables 12 and 16 bit SATA Commands over UAS when used with Seagate HDD enclosures. This usb_storage quirk is "t" instead of "u" which forces the device into USB BOT mode. The only way to make S.M.A.R.T. to work with USB HDD enclosure is to use UAS without limitations - that is, no quirk of any kind. Note that full UAS support has been disabled on all Seagate enclosures by default because Seagate had such a poor track record with multiple products. The quirk "t" is enough to avoid the issue and it will not cause equal performance slowdown as the "u" quirk. Note that if you disable all quirks with known-bad Seagate enclosure the S.M.A.R.T. will work but you risk random data corruption if you write any data on the disk. I guess remounting the disk read-only, disabling the "t" quirk, doing S.M.A.R.T. query, re-enable the "t" quirk and remounting read- write could be considered a safe workaround if you really need the S.M.A.R.T. data. More details about possible usb_storage.quirks: https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1810215 Title: for Seagate USB drive enclosures, SAT (e.g. smartmontools, hdparm) works on kernel 4.13 but not on 4.15 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1810215/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs