gmirror per partition
dalroi at solfertje.student.utwente.nl
Fri Jul 3 11:37:12 UTC 2009
On Jul 3, 2009, at 12:12 PM, Anton Shterenlikht wrote:
> now to mirror root partition.
> My problem is that root is mounted and cannot (?) be unmounted,
> unlike /efi,
> on the live system.
> # gpart add -b 819234 -s 1048576 -t freebsd-ufs da1
> da1p2 added
> # gmirror label -vb round-robin root /dev/da0p2
> gmirror: Can't store metadata on /dev/da0p2: Operation not permitted.
> If I create gmirror on da1, the spare disk:
> # gmirror label -vb round-robin root /dev/da1p2
> Metadata value stored on /dev/da0p1.
> so that
> # gmirror status
> Name Status Components
> mirror/efi COMPLETE da0p1
> mirror/root COMPLETE da1p2
> then I still cannot insert da0p2
> # gmirror insert root da0p2
> gmirror: Cannot access provider da0p2.
> So how can I gmirror root partion on a live system?
You're almost there... I did this a while ago, can't remember when,
but I just upgraded the system that had this from FreeBSD 6.3 of
sometime in 2006 to 7.2.
What I believe I did from this point on was:
Copy everything from the root partition to mirror/root.
Modify /etc/fstab to mount root on mirror/root.
Now the original root partition isn't mounted anymore, so we can do
operate on it's geom stuff.
gmirror insert root da0p2
That should be it.
If that doesn't work you can always boot off a live file-system CD/DVD
and perform these actions from there. You won't have man pages in that
case though, or at least I couldn't find a way to read them off the
DVD last I tried.
One thing I'd like to warn about at this point:
If you ever upgrade to a kernel with a newer geom metadata version and
that new kernel crashes, you're left with a system where the new
kernel can't boot at all while the old kernel can't mount the root
mirror as it's now of a version it can't handle.
You can however mount a single geom provider of that root file system
(/dev/da1p2 for example) to try to fix things.
That file-system WILL be dirty, but DON'T run fsck on it or you will
destroy it's contents. That's what happened to my upgrade above...
Thankfully it was only my root partition with hardly any data on it
and I did make level 0 dumps before the upgrade, but I needed to
restore that FS from a fixit shell without man pages. Augh!
> many thanks
> Anton Shterenlikht
> Room 2.6, Queen's Building
> Mech Eng Dept
> Bristol University
> University Walk, Bristol BS8 1TR, UK
> Tel: +44 (0)117 928 8233
> Fax: +44 (0)117 929 4423
> freebsd-current at freebsd.org mailing list
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If you can't see the forest for the trees,
cut the trees and you'll see there is no forest.
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