Date: Wed, 07 Aug 2002 08:54:41 -0500 From: "Jack L. Stone" <jackstone@sage-one.net> To: Rob Ellis <rob@web.ca>, freebsd-questions@FreeBSD.ORG Subject: Re: Questions about vinum and failure of root partition Message-ID: <3.0.5.32.20020807085441.02d62db8@mail.sage-one.net> In-Reply-To: <20020807132232.GA47309@web.ca> References: <005e01c23dcb$061acbb0$6602a8c0@swbell.net> <200208070101.g7711iU06306@clunix.cl.msu.edu> <005e01c23dcb$061acbb0$6602a8c0@swbell.net>
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At 09:22 AM 8.7.2002 -0400, Rob Ellis wrote: >one workaround for having to have a non-mirrored boot >partition with 2 disks is to put 2 slices on each >disk -- one for fbsd system partitions, and one for >mirrored data... > > ad0s1, ad2s1 -> small bootable slices for os partitions > ad0s2, ad2s2 -> rest of the disk for mirrored data partitions > >install fbsd on ad0s1, with partitions for / and swap >and maybe tmp. partition ad2s1 the same way. create >your vinum mirror using partitions on ad0s2 and ad2s2 >and symlink /var and whatever else you want to directories >on the mirror. > >then create a backup of the fbsd partitions on >the first disk, copying everything from ad0s1 to ad2s1: > > dd if=/dev/ad0s1 of=/dev/ad2s1 bs=102400 > >fsck the newly copied filesystems: > > # a, e... are partitions > for i in a e f g h ; do fsck -y /dev/ad2s1$i ; done > >install ad0's master boot record to ad2 > > fdisk -B /dev/ad2 > >and now the second disk is a bootable copy of the >first; if the first disk fails, you swap the cables >on the disks (make the secondary the primary) >and reboot -- the os and vinum come back up. > >- rob > Rob: Thanks for this first time I have seen anything about filling the void on the mirroring technique when using vinum. That missing ingredient has always seemed to been a drawback and a deterrent. My side question is about the "dd" command. Why did you choose the parameter "bs=102400" rather than any other?? I've been using 8192, but have seen this switch all over the map, including 1024 to 1M. I know it can make a difference in the time to do an image because of the sizing. With 8192, I do an entire 40GB HD in 39 mins (1.4GHz CPU) but takes 49 mins for a 1GHz CPU. Best regards, Jack L. Stone, Administrator SageOne Net http://www.sage-one.net jackstone@sage-one.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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