Am Fri, 15 Apr 2016 08:26:23 -0600 Warner Losh <i...@bsdimp.com> schrieb:
> On Fri, Apr 15, 2016 at 7:51 AM, O. Hartmann <ohart...@zedat.fu-berlin.de> > wrote: > > > On Thu, 14 Apr 2016 22:19:23 -0600 > > Warner Losh <i...@bsdimp.com> wrote: > > > > > On Thu, Apr 14, 2016 at 9:56 PM, Warren Block <wbl...@wonkity.com> > > wrote: > > > > > > > On Thu, 14 Apr 2016, Warner Losh wrote: > > > > > > > > The CAM I/O scheduler has been committed to current. This work is > > > > described > > > >> in https://people.freebsd.org/~imp/bsdcan2015/iosched-v3.pdf though > > the > > > >> default scheduler doesn't change the default (old) behavior. > > > >> > > > >> One possible issue, however, is that it also enables NCQ Trims on ada > > > >> SSDs. > > > >> There are a few rogue drives that claim support for this feature, but > > > >> actually implement data corrupt instead of queued trims. The list of > > known > > > >> rogues is believed to be complete, but some caution is in order. > > > > > > > > > > > > > > > Is the list of drives queryable? Is there an easy way to tell if the > > > > currently-connected drives are on the list? > > > > > > > > > > /usr/src/sys/cam/ata/ata_da.c has the list. > > > > > > dmesg will tell you if it detected a bad one since it prints the drive's > > > quirks. > > > But that's no big deal, because the bad one work just fine if you never > > > issue > > > a NCQ TRIM. This small group of drives were early adapters of this > > > technology > > > > > > Here's the full list of known rogues: > > > > > > Crucial/Micron M500 (all firmware prior to MU07) > > > Micron M510 MU01 firmware (newer firmware is good) > > > Crucial/Micron M550 MU01 firmware (newer firmware is good) > > > Crucial MX100 MU01 firmware (newer firmware is good) > > > FCCT M500 all firmware > > > Samsung 830 all firmware > > > Samsung 840 all firmware > > > Samsung 850 all firmware > > > > This is funny, > > > > ALL of our Fujitsu Workstations and those I use pprivate do have Micron SSD > > drives (Fujitsu) and Samsung SSD (830 and 840). > > > > Which Micron drives? I'm not familiar with the 'Fujitsu' model for that > line. The boxes are Celsius M-7XX series boxes, I checked but forgot, but I think its M600 type SSDs (sold with workstations Marsch/April 2015). > The newer ones are fine, the ones listed above with the MU01 firmware > being bad have MU02 firmware (or newer) available that fixes the problem. > The M500's firmware exists, but I don't know how available it is. So for > Micron, solutions to the problem exist. > > The 830 and 840 apparently claim support, but are in the class of drives > that simply fail to actually work in what may be a reasonable way to detect. > There's code to do the fallback in there now, but I'm not so sure that it is > working given some of the reports I've seen. Maybe I need to try to but > a couple of these drives to see. I was mistaken, I personally use some 830 and since a couple of weeks 850 (not 840). Both are marked as you described. > > So - they are the most popular/used drives in a more "professional" > > environment these days and they get blacklisted :-( > > > > At least for the micron drives, you don't want to use NCQ trim on the > versions listed. It's data corruption roulette. For newer drives, it is > fine. > The performance will certainly be no worse than it was before my > commit. > > Warner > _______________________________________________ > email@example.com mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
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