Vinum + new disk for mirror
rob at web.ca
Tue Apr 6 07:44:56 PDT 2004
On Tue, Apr 06, 2004 at 09:40:09AM +0930, Greg 'groggy' Lehey wrote:
> On Monday, 5 April 2004 at 19:09:46 -0400, Rob Ellis wrote:
> > On Tue, Apr 06, 2004 at 08:12:49AM +0930, Greg 'groggy' Lehey wrote:
> >> On Monday, 5 April 2004 at 12:42:12 -0400, Rob Ellis wrote:
> >>> We have a machine with a vinum mirror, all the partitions except
> >>> the root partition mirrored between two disks. The second
> >>> disk has died and I want to replace it. I can't find a disk exactly
> >>> the same, so I have a disk that's bigger (80GB, old one was 60GB).
> >> That's not a problem. Vinum doesn't use disks.
> >>> Can I...
> >>> - shutdown, replace the bad disk with the bigger new disk
> >>> - boot single user, mount /
> >>> - copy the good disk to the new disk with:
> >>> dd bs=128k if=/dev/ad0 of=/dev/ad2
> >>> - vinum start
> >>> - restart any stale subdisks (?)
> >>> - ...
> >> You can, though you'll need a couple more steps. But why don't you
> >> follow the instructions?
> >> http://www.vinumvm.org/vinum/replacing-drive.html or
> >> http://www.vinumvm.org/cfbsd/vinum.pdf.
> > Oops.
> > I guess what I was wondering about / wanted to be clear about is
> > whether the 'dd' of /dev/ad0 to /dev/ad2 is ok between disks that
> > aren't the same. I was hoping that it would copy the partition table
> > and boot blocks (I don't care about the extra space at the end of
> > the bigger disk)...
> You should do.
> > I was also hoping (blindly) that the vinum config would get copied
> > and that the dd of the data would speed up the rebuilding of the
> > mirror...
> The Vinum config would, indeed, get copied. But that's not the way to
> do it.
> > But it sounds like what I should do is manually configure the
> > partition table on the new disk to match the old one and then follow
> > the instructions? :-)
> No, make the partition table to cover the entire disk. Why throw away
To make it simpler? Because I don't need the space?
I've got 8 partitions on the existing disk -- 5 filesystems, 1 swap,
1 vinum which overlaps 4 of the filesystems, and 'c' -- which I think
is the limit for partitions? (4.9).
I suppose I could make the un-mirrored root partition on the new disk
much larger, but I don't want to do that... or I guess I could put a
filesystem on a refigured 'c' on the new disk... but I don't really
want to do that either. Anyway, I could do it later by editing the
copied partition table if it turns out I do need the space...?
I probably will do it the recommended way :-)
but I'm just curious now if dd would work. It does seem simpler,
and I won't have to try to edit a partition table with overlapping
partitions with 'disklabel'. And maybe the copied vinum config
will just work...?
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