The partition table on device sdb was unreadable

[Dave Cross]

I'm trying to do a new F8 installation on a system that is currently
running F7. Th system has two SATA disks. The first (sda) is 160 GB
and contains the boot partition, the swap and an LV which mounts /.
The second disk (sdb) is 320 GB and contains another logical volume
group containing two LVs, one for /home and one for /data.

What I'd like to do is to reinstall onto / but leave all of the data
in /home and /data untouched.

But when the installation routine gets to the section where it starts
to look at the disk partitions, it gives and error saying "The
partition table on device sdb was unreadable". And it then won't let
me set the mount points for the data LVs or mark them not to be
formatted.

That doesn't seem to be a problem for the existing installation. That
can read the partition table without any problems.

Am I trying to do something that you can't do? Is it impossible to
reinstall from scratch but leave an existing LV untouched?

I'm worried about proceeding as I really don't want to lose the data
on this disk. And I don't really have the time (or space) to back it
up.

Any advice?

Cheers,

Dave...