From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bakul Shah Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (1.0) Date: Sat, 3 Feb 2018 19:58:46 -0800 Message-Id: References: In-Reply-To: To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Subject: Re: [9fans] SMART: Silly Marketing Acronym, Rebuts Truth Topicbox-Message-UUID: cbc1bb3e-ead9-11e9-9d60-3106f5b1d025 On Feb 3, 2018, at 3:59 PM, Lyndon Nerenberg wrote: >> The interesting thing (for me) was that >> the SMART data from the drive gave it an all clear right to the end. But >> unlike the SSDs, there was plenty of behavioural warning to remind me to >> have the backups up to date and a spare at the ready... >=20 > FWIW, of the three-four dozen or so drives I have actively SMART monitored= over the years, of the ones that failed, *not* *one* gave a SMART warning b= efore dying. >=20 > That includes a spinny disk in one of my Mac Minis. Of anyone, I would ex= pect Apple to be in bed with their HD suppliers enough to have HD firmware t= hat reliably reports SMART errors (since the disk utilities do pay attemtion= to it). I spent a month listening to that drive's heads slam back to the h= ome position as it tried to recalibrate itself, before eventually dying. To t= he bitter end, SMART reported "a-ok boss!" I have only monitored disks @ home and for them SMART does report all sorts of things. For recalibration to have kicked in, you should seeing lots of errors. It=E2=80=99s possible Apple s/w dumbs it down & presents jus= t one binary choice to the user but the underlying data should be there. It=E2=80=99= s usually host s/w that falls short. Given disks=E2=80=99 bathtub error curve,= s/w should show error rate as a graph (as a function of time) from the beginning and recommend replacement as the rate starts climbing again. Ideally it should even compare it with averaged error data collected by the vendor. History and good visualization can be very helpful.=