Re: glabel+gmirror (8.0-RC1 problem)

On Mon, Sep 28, 2009 at 08:37:56PM +0200, Oliver Lehmann wrote:
> Hi Pawel,
> 
> Pawel Jakub Dawidek wrote:
> 
> > Does anything change between you upgrade from BETA3 and RC1? For example
> > gmirror was compiled into the kernel before and now is loaded as module
> > or something similar?
> 
> Nope, it was a clean BETA3 installation with the default GENERIC kernel
> which has afaik geom_label in kernel, but not geom_mirror (nevertheless I
> loaded geom_label.ko at boottime as well as geom_mirror)
> The same with RC1 - clean and fresh installation with the default GENERIC
> kernel and geom_label in kernel (default), but still loaded as module at
> boottime as well as geom_mirror.
> 
> > Could you test this patch:
> > 
> > 	http://people.freebsd.org/~pjd/patches/improved_taste.patch
> 
> This makes gmirror+glabel work again on RC1

Thanks for confirmation.

> One thing which I noticed. I labeled in single user mode, my root
> partition with tunefs - as well as all my other partitions. After this
> was done, I remounted my root partition (mount -rw /) and changed my
> fstab to use the new geom labels instead. But somehow this "killed" the
> new root-label of my mirror/gm0s1a partition. After I rebooted, the label
> was gone and I had to manually specify the root partition
> ufs:mirror/gm0s1a to mount. All the labels of my other mirrored
> partitions where there (usr, tmp, var). I then rebooted once more into
> single user mode (specified once more the root partition manually) and
> did a tunefs -L once more. Then I rebooted directly and the label is now
> there.
> 
> Is it possible that mount -rw / (which remounts /dev/mirror/gm0s1a) could
> have been killed the freshly given label?

Yes. tunefs(8) updates only on-disk super-block, but the kernel holds
super-block that was read before. Now when you do 'mount -rw /' the
in-kernel super-block is stored to the disk, and there is nothing about
your label in there, so it gets overwritten.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd_at_FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!