upgrading with LVM file systems

[Tony Schreiner <schreian bc edu>]

I'm getting ready to upgrade a file server from RedHat 8, to RHEL 3.
The home and data disks are on an external RAID array, and they are on 
an LVM (1.0.3) managed file system.

I don't have much experience with LVM so I'm a bit nervous about the 
upgrade. I've read the LVM-Howto, but there is not much advice on OS 
upgrades. Probably everything will go ok, but if I should lose the LVM 
information, I'm asking what I need to know ahead of time, to recover 
it.

vgdisplay -v shows two volumes /dev/sda and /dev/sdb on the array. I 
think it's 2 volumes because of a maximum number of disks limit. The 
two volumes are part of a single volume group, and a single logical 
volume on top of that.

Should I vgexport before doing the upgrade? Any other hints would be 
appreciated.

Thanks,