Date: Wed, 23 Apr 2014 09:20:42 -0700 From: Gennadiy Gulchin <ggulchin@icloud.com> To: Karl Denninger <karl@denninger.net> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org> Subject: Re: ZFS unable to import pool Message-ID: <6305B1EB-F091-47FB-ADEA-6C2EF72C8FBD@icloud.com> In-Reply-To: <5357D7E7.605@denninger.net> References: <B493BD80-CDC2-4BA6-AC14-AE16B373A051@icloud.com> <20140423064203.GD2830@sludge.elizium.za.net> <B1024D84-EBBE-4A9B-82C4-5C19B5A66B60@icloud.com> <20140423080056.GE2830@sludge.elizium.za.net> <20140423091852.GH2830@sludge.elizium.za.net> <20140423100126.GJ2830@sludge.elizium.za.net> <5357937D.4080302@gmail.com> <72E79259-3DB1-48B7-8E5E-19CC2145A464@icloud.com> <888649C4-CC66-48A6-9901-BEA93D1BBFA3@mail.turbofuzz.com> <FC0D5991-8F8D-41D5-BB50-AB840C29F362@icloud.com> <5357CC7B.2090003@denninger.net> <CAFHbX1Lh7qCsE%2Bgxmf9jBcu5c1Wr_ApHB9SP_VWYnkNj3N_5HQ@mail.gmail.com> <5357D7E7.605@denninger.net>
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Thanks for your help guys! The only think that makes my hope still survive is the disk I have added is the sAme physicscal disk as in raidz1 pool. Or having Just one disk outside of raidz1 and making this disk unavailable causes the whole array to tank? --Gena > On Apr 23, 2014, at 8:10 AM, Karl Denninger <karl@denninger.net> wrote: > >> On 4/23/2014 10:03 AM, Tom Evans wrote: >>> On Wed, Apr 23, 2014 at 3:21 PM, Karl Denninger <karl@denninger.net> wrote: >>> /*Filesystem based "redundancy" is not a backup strategy!*/ >> It's my (home) backup strategy :( >> >> Very few cost efficient ways to backup 15TB+ of data other than >> redundant spinning rust. > I have a large home system as well. > > But I do back it up to other spinning pieces of rust, and rotate the backups out to a bank safe-deposit box. If I make a terrible mistake (or my hardware and/or software does) I have a means of recovery. There are no guarantees of course in that I COULD wind up with a bad disk in the safe deposit box, but if my house burns down I have a shot at recovery with high odds of success -- an act that would otherwise be impossible. Partitioning my data off into "essentially archival, read-almost-only" and "active" means that the former needs to be updated rarely and the former is of small enough size that I don't go crazy doing it either in money or time. > > And I *HAVE* had things like this happen -- twice in the last 20 years I've had a disk adapter go insane and scribble on MULTIPLE spindles at once. There is no RAID strategy that will protect you against this event; you either have a backup or you're done. > > ZFS actually makes this easier with send/receive and the ability to import a pool, send to it and then export it. The backup pool can have compression turned on where for performance reasons it may not make sense for the online pool to do so. And you can rotate that out fairly easily too; you can take a 2-way mirror, add a third disk and let it resilver, then split the third one off and remove it, giving you a dismounted copy you can then stick in a box and yet if you need it -- it's there. > > -- > -- Karl > karl@denninger.net > >
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