Date: Sun, 23 Mar 2014 20:08:43 +0100 From: Ondra Knezour <knezour@weboutsourcing.cz> To: Karl Denninger <karl@denninger.net>, freebsd-stable@freebsd.org Subject: Re: ZFS cautions (pool flag additions committed) Message-ID: <532F313B.5040809@weboutsourcing.cz> In-Reply-To: <532F1ED8.8010004@denninger.net> References: <532F1ED8.8010004@denninger.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Dne 23.3.2014 18:50, Karl Denninger napsal(a): > When ZFS code imports are brought forward that add feature flags there > is a potential time bomb for existing users in that creation of a new > pool becomes non-revertible (except read-only!) with regard to mounting > on older revisions of the code. > > The same thing happens if you do a "zpool upgrade" of course, but at > least that's an explicit act. You might not realize that you're at risk > on a pool create, however, unless you **carefully** scrutinize the flags > that were on the last version compared against the current one. > > The primary "gotcha" here occurs if you don't upgrade your emergency > boot media and for some reason you need to boot from a CD or USB key -- > you can be left SEVERELY screwed, and since -RELEASE is typically not > rebuilt when this happens if you don't have a second machine laying > around on which you can build a RELEASE image.... > > I've caught this twice now since 10.0-RELEASE shipped and, while I > haven't been bit by it, it serves as a caution because eventually > someone tracking -STABLE is going to get badly hurt and be left with an > unrepairable system. IMHO there should be some sort of notice on the > list when new zpool feature flags show up so you're fairly warned that > building a new emergency boot media copy is required if you intend to > track -STABLE on a continuing basis. > Excellent candidate for the /usr/src/UPDATING file? -- Ondra Knezour
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?532F313B.5040809>