Date: Wed, 02 Jan 2008 08:47:43 -0800 From: "Chris H." <chris#@1command.com> To: John Nielsen <lists@jnielsen.net> Cc: freebsd-stable@freebsd.org Subject: Re: gmirror on 7B4 Message-ID: <20080102084743.xtecj951wogwws8w@webmail.1command.com> In-Reply-To: <20080102112230.g7p1bj3sdck488g8@newwebmail.jnielsen.net> References: <20080102002651.r72jwx0pgk4000c8@webmail.1command.com> <20080102070518.ki0v7vxkgo0cossg@webmail.1command.com> <20080102111751.5huybrwosgs0ccos@newwebmail.jnielsen.net> <20080102112230.g7p1bj3sdck488g8@newwebmail.jnielsen.net>
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Quoting John Nielsen <lists@jnielsen.net>: > I'm not sure I remember everything from earlier in this thread so I > don't know if it's relevant, BUT you can't boot from a gstripe volume > (or from a gconcat one AFAIK). Inferring from your fstab example > below it doesn't sound like you intend to but I just wanted to be > sure. Are you sure? I read that using gmirror requires /kernel to be located in the /boot slice and everything else (all other slices) can be mirrored safely. But in all my reading (man pages, FBSD handbook, asstd articles) I haven't seen anything indicating booting wasn't possible from a gstripe volume. For the record, FSTAB (on da3): /dev/da3s1b none (swap) /dev/da3s1a / /dev/da3s1d /var Thanks for your response. Chris > > Quoting John Nielsen <john@jnielsen.net>: > >> Quoting "Chris H." <chris#@1command.com>: >> >>> Quoting "Chris H." <chris#@1command.com>: >>> >>>> Hello, >>>> I seem to remember a similar question being asked in the past. But never >>> ---8<---snip---8<--- >>>> I had originally intended to create a raid mirror on the whole lot of HD's >>>> during the install process. But I wasn't presented, nor could I find that >>>> option during install. So, due to lack of time, pushed it off till later, >>>> and simply installed onto the one HD. Now to my question(s)... >>>> >>>> Where is the option to create, and install to a gMIRRORED drive-set? >>> ---8<---snip---8<--- >>>> 2) In my cases above, I'm interested in RAID-0 (mirroring for /volume/ >>>> not redundancy). >>>> >>> >>> OK, my mistake... >>> Seems for my application (RAID0), *gstripe* is what I should >>> be using. >>> Q: But RAID0 provides 0 redundancy. How will you cope with data loss? >>> A: Complete backups occur twice daily and I (we) use IP RAID0 - >>> eg; 2 different servers have/provide the same data, and the DNS provides >>> "round-robin". Thereby spreading the requests roughly equal across >>> both servers. >>> So, given my new found knowledge. I felt I should probably ask before >>> potentially clobbering (breaking) the server I'll be attempting this on. >>> Will the following accomplish my goal? >>> Current setup: >>> /dev indicates the following: >>> da0, da0c, da0cs1, da0s1, da0s1c >>> da1, da1c, da1cs1, da1s1, da1s1c >>> da2, da2c, da2cs1, da2s1, da2s1c >>> ...and the following, which FreeBSD is installed on: >>> da3, da3s1, da3s1a, da3s1b, da3s1c, da3s1d >>> All drives are of same size/make/model. >>> >>> Given the above, I intend to issue the following: >>> >>> # gstripe label -v -s 131072 bigstripe \ >>> /dev/da0 /dev/da1 /dev/da2 /dev/da3 >>> >>> # newfs -U /dev/stripe/bigstripe >>> >>> # mount /dev/stripe/bigstripe /bigstripe >>> >>> # echo 'geom_stripe_load="YES"' >> /boot/loader.conf >>> >>> # echo '/dev/stripe/bigstripe /bigstripe ufs rw 2 2' >> /etc/fstab >> >> Yes, this should be fine (though you may need to do a "gstripe load" >> near the beginning). >> >>> Or do/should I issue: >>> >>> # gconcat label -v extradisks /dev/da0 /dev/da1 /dev/da2 >>> >>> # gstripe label -v bigstripe /dev/da3 /dev/concat/extradisks >>> >>> # bsdlabel -wB /dev/stripe/bigstripe >>> >>> # newfs -U /dev/stripe/bigstripe >>> >>> # mount /dev/stripe/bigstripe /bigstripe >> >> No, assuming the disks are (roughly) the same size there's no reason >> to use gconcat, and in this case doing so will likely hurt >> performance in addition to adding complexity. gconcat is generally >> just for JBOD-type scenarios and it sounds like you're after RAID0 >> which is what gstripe is for. >> >> JN >> >>> Thank you for all your time and consideration. >>> >>> Chris >>> >>> P.S. I know this is a bit noisy. I intend to keep it brief. >>> Thank you for your understanding. :) >>> >>>> -- >>>> panic: kernel trap (ignored) >>>> >>>> >>>> >>>> _______________________________________________ >>>> freebsd-stable@freebsd.org mailing list >>>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable >>>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >>>> >>> >>> -- >>> panic: kernel trap (ignored) >>> >>> >>> >>> _______________________________________________ >>> freebsd-stable@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable >>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >>> >>> >> >> >> > > > -- panic: kernel trap (ignored)
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