Date: Sun, 23 Mar 2014 12:50:16 -0500 From: Karl Denninger <karl@denninger.net> To: freebsd-stable@freebsd.org Subject: ZFS cautions (pool flag additions committed) Message-ID: <532F1ED8.8010004@denninger.net>
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[-- Attachment #1 --] 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. -- -- Karl karl@denninger.net [-- Attachment #2 --] 0 *H 01 0 + 0 *H O0K030 *H 01 0 UUS10UFlorida10U Niceville10U Cuda Systems LLC1 0UCuda Systems LLC CA1/0- *H customer-service@cudasystems.net0 130824190344Z 180823190344Z0[1 0 UUS10UFlorida10UKarl Denninger1!0 *H karl@denninger.net0"0 *H 0 bi՞] MNԿawx?`)'ҴcWgR@BlWh+ u}ApdCF JVй~FOL }EW^bچYp3K& ׂ(R lxڝ.xz?6 &nsJ +1v9 v/( kqĪp[vjcK%fϻe?iq]z lyzFO'ppdX//Lw(3 JI A*S#՟H[f|CGqJKoo y.oEuOw$ /섀$삻J9b|A P~8]D1YI<"""Y^T2iQ2 b yH)] Ƶ0y$ _N 6XqMC 9 XgώjGTP"#nˋ"Bk1 00 U 0 0 `HB0 U 0, `HB OpenSSL Generated Certificate0 U |8 ˴d[20 U #0]Af4 U3x&^"408 `HB+)https://cudasystems.net:11443/revoked.crl0 *H gBwH] j\x`( &gW32"Uf^. ^Iϱ k!DQA g{(w /)\N'[ oRW @C HO>)XrTNɘ!u`xt5(=f\-l3<@C6mnhv##1ŃbH͍_Nq aʷ?rk$^9TIa!kh,D -ct1 0001 0 UUS10UFlorida10U Niceville10U Cuda Systems LLC1 0UCuda Systems LLC CA1/0- *H customer-service@cudasystems.net0 + ;0 *H 1 *H 0 *H 1 140323175016Z0# *H 1@Au蜢[m0l *H 1_0]0 `He*0 `He0 *H 0*H 0 *H @0+0 *H (0 +71001 0 UUS10UFlorida10U Niceville10U Cuda Systems LLC1 0UCuda Systems LLC CA1/0- *H customer-service@cudasystems.net0 *H 101 0 UUS10UFlorida10U Niceville10U Cuda Systems LLC1 0UCuda Systems LLC CA1/0- *H customer-service@cudasystems.net0 *H Y= QxcPra8 )! ͖!56 ~{/ ͏0=he*N[@9QZw4Ü$T %hF/0&j hŒ$Dtq5#y&0? WaΞ2` :R@̘ۗ;d*ɣ܌:Lh mD G~8Cڤ"S ,X]!TtcvVuQ<= DM~`cAi(* $lؤ#䀾ī1U Kfnį ql,EQo 2%{Wy,0 ,Q9}*yf{$7 ^ϡZľyBOu|<nJ>ϋ;PD]iäc C>=zdV=⦜m?S{}vPQj.)t2!
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