On 30 November 2016 at 19:09, Chris Murphy <li...@colorremedies.com> wrote: > On Wed, Nov 30, 2016 at 7:37 AM, Austin S. Hemmelgarn > <ahferro...@gmail.com> wrote: > >> The stability info could be improved, but _absolutely none_ of the things >> mentioned as issues with raid1 are specific to raid1. And in general, in >> the context of a feature stability matrix, 'OK' generally means that there >> are no significant issues with that specific feature, and since none of the >> issues outlined are specific to raid1, it does meet that description of >> 'OK'. > > Maybe the gotchas page needs a one or two liner for each profile's > gotchas compared to what the profile leads the user into believing. > The overriding gotcha with all Btrfs multiple device support is the > lack of monitoring and notification other than kernel messages; and > the raid10 actually being more like raid0+1 I think it certainly a > gotcha, however 'man mkfs.btrfs' contains a grid that very clearly > states raid10 can only safely lose 1 device. > > >> Looking at this another way, I've been using BTRFS on all my systems since >> kernel 3.16 (I forget what exact vintage that is in regular years). I've >> not had any data integrity or data loss issues as a result of BTRFS itself >> since 3.19, and in just the past year I've had multiple raid1 profile >> filesystems survive multiple hardware issues with near zero issues (with the >> caveat that I had to re-balance after replacing devices to convert a few >> single chunks to raid1), and that includes multiple disk failures and 2 bad >> PSU's plus about a dozen (not BTRFS related) kernel panics and 4 unexpected >> power loss events. I also have exhaustive monitoring, so I'm replacing bad >> hardware early instead of waiting for it to actually fail. > > Possibly nothing aids predictably reliable storage stacks than healthy > doses of skepticism and awareness of all limitations. :-D > > -- > Chris Murphy > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
Please, I beg you add another column to man and wiki stating clearly how many devices every profile can withstand to loose. I frequently have to explain how btrfs profiles work and show quotes from this mailing list because "dawning-kruger effect victims" keep poping up with statements like "in btrfs raid10 with 8 drives you can loose 4 drives" ... I seriously beg you guys, my beating stick is half broken by now. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
