[linux-lvm] recovering a bad physical volume

[Matthew Johnson]

On Wed, 17 Jul 2002, Patrick Caulfield wrote:

> Hmm, that message is a bit odd. Check that the partition sizes really do match
> what LVM thinks they ought to be. vgcfgrestore -ll -n <vg> will show you this.
>
> If the sizes match up and the disk is OK there's no reason why the filesystem
> shouldn't mount.
>

OK, I ran that, and that PV has 756 extents, and 746*4096*1024 is
3170893824. From fdisk, (end sector - start sector)*1008*512 the partition
is 3176054784, a difference of 5160960, or 10 cylinders. Now, I'm sure I
copied the values for the partition sizes back in fine - but possibly I
accidentally made that one 10 too large.

Now, on that drive I had <hde5 hde6 hde7> in the extended partition. I
wanted to reduce hde5 in size, and insert hde8 between 5 & 6, then add
that to the lvm. With fdisk, you have to delete, then re-add 5 as the
smaller size. Unfortunately when you do that it renumbers 6 & 7 to 5 & 6.
Hence to keep the correct partition numbers (I don't know how to change
where a vg looks for its pvs for example) You have to delete them all, and
add them in number, not location, order.

Since hde7 worked fine, I assume the end cylinder of hde6 is correct, and
if I just move the start cylinder up 10, then that will then work. Is
there a better way to do this than with fdisk? since I'll have to delete
them all again and then create them, to keep the numbering correct.

Thanks again,

Matt