Date: Sun, 12 Dec 2004 16:50:12 -0700 From: Ken Gunderson <kgunders@teamcool.net> To: freebsd-geom@freebsd.org Subject: Re: gmirror confusion Message-ID: <200412121650.12823.kgunders@teamcool.net> In-Reply-To: <200412101947.52728.kgunders@teamcool.net> References: <200412101947.52728.kgunders@teamcool.net>
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On Friday 10 December 2004 07:47 pm, Ken Gunderson wrote: > Hello: > > Been fighting gmirror for longer than I want to admit and going to > have to break down and ask for help on what at first blush seems > should be trivial... Would somebody please elaborate upon Pawel's > post in the gmirror problmes thread: > > <pjb> > The safest way to do what you want is to: > > # gmirror label <name> ad1 > create slices and partitions on /dev/mirror/<name> > create file system > copy data from ad0 to <name> > change /etc/fstab to boot from /dev/mirror/<name>s1a or > something > reboot > # gmirror insert <name> ad0 > </pjb> > > I have two disks, ad0 and ad2 that I'd like to mirror. In the past > would have just bootstrapped vinum. Gmirror seems like a better way > to go for this type of application but I'm only recently using 5.3 on > production machines so haven't had the chance to become as familiar > with geom as I probably should be. > > I can get the mirror configured with the live files system trick, but > not the above, which Pawel mentions as the "safest" way to handle > this. > > For example, I've searched archives and seen references to both > > 1) "create slices and partitions on /dev/mirror/<name>" > > as well as > > 2) "create slices and partitions on provider" > > As well as confusion about whether the mirror's label should have the > 16 sector offset thrown at it by bsdlabel, or whether I should just > clone the label from the drive I did the install on. > > I'm also curious whether anyone has done any performance testing of > the different balance options. For booting from 2 mirrored drives, I > assume either "load" or "round-robin" would be the options of choice? > > TIA-- I'll be lame and follow up my own post... First, sorry that I confused "provider" with "consumer", so that question is moot. However, I note the following: >>>>>>> build# bsdlabel mirror/mirror0s1 # /dev/mirror/mirror0s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 524288 0 4.2BSD 2048 16384 32776 b: 4194304 524288 swap c: 78156162 0 unused 0 0 # "raw" part, don't edit d: 1048576 4718592 4.2BSD 2048 16384 8 e: 1048576 5767168 4.2BSD 2048 16384 8 f: 8388608 6815744 4.2BSD 2048 16384 28552 g: 16777216 15204352 4.2BSD 2048 16384 28552 h: 46174594 31981568 4.2BSD 2048 16384 28552 build# bsdlabel /dev/mirror/mirror0s1 # /dev/mirror/mirror0s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 524288 63 4.2BSD 2048 16384 32776 b: 4194304 524351 swap c: 78156162 63 unused 0 0 # "raw" part, don't edit d: 1048576 4718655 4.2BSD 2048 16384 8 e: 1048576 5767231 4.2BSD 2048 16384 8 f: 8388608 6815807 4.2BSD 2048 16384 28552 g: 16777216 15204415 4.2BSD 2048 16384 28552 h: 46174594 31981631 4.2BSD 2048 16384 28552 partition c: partition extends past end of unit bsdlabel: partition c doesn't start at 0! bsdlabel: An incorrect partition c may cause problems for standard system utilities partition h: partition extends past end of unit <<<<<<<<<<<<<<<<<<< Per man page for bsd label: "When specifying the device, the /dev/ path prefix may be omitted; the bsdlabel utility will automatically prepend it." Hence I was getting confused about seeming eratic bsdlabels, until I figured out that the return was consistent, but dependent upon whether I prepended "/dev" or not, at least when applied to gmirror provider. Is this 1) a bsdlabel or gmirror issue, and 2) which return should I believe? Thanks. -- Best regards, Ken Gunderson GPG Key-- 9F5179FD "Freedom begins between the ears." -- Edward Abbey
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