I understand:
- you are not booting from hda or hdc
- hdc still holds a valid LVM VGDA
- likely the first sector of hda got blown away (by lilo)
- you don't have any /etc/lvmconf/ VGDA backup files on disk/tape
(if not so use vgcfgrestore(8) in order to restore metadata to /dev/hda!)
I'm assuming based on the data below:
- your 2 physical volumes are equal in size
- you had just 1 logical volume spread over both physical volumes using
all of the VG's capacity
- all of your VGDA with the exception of the physical volume structure,
which was sitting at the very beginning of hda is still there and
likely valid
*If* the above assumptions are correct, your option is to copy the first
sector of /dev/hdc over to /dev/hda with
"dd if=/dev/hdc bs=512 count=1 of=/dev/hda" *and* change it with a hex editor.
In order to find the correct offsets into the first sector on /dev/hda to
change, look at lvm.h (of LVM 0.8final!) and the definition of pv_disk_t in
that header file.
At least you need to change the physical number (pv_number); set it to 1.
In case the above assumptions are not correct for eg. the sizes of the PVs
differ, you need to change pv_size, pe_total and pe_allocated as well.
Please get back to me if this is the case.
BTW: we are working on the enhancement of our LVM checker in order
to support such repairs. Not very helpfull for you nor, I know :(
Don't forget to check your /etc/lilo.conf to make sure, that lilo doesn't
tamper with the first sector on /dev/hda again!