[linux-lvm] LVM ate my data!

[lvm-mail at wbh.org]

Hiya.
    I've just upgraded my kernel, and on booting my LVM setup isn't
recognised. Going back to the old kernel, it still isn't.
Running vgscan gives:
vgscan -- reading all physical volumes (this may take a while...)
vgscan -- found inactive volume group "pvg"
vgscan -- ERROR "vg_read_with_pv_and_lv(): allocated LE of LV" can't get data of volume group "pvg" from physical volume(s)
vgscan -- ERROR "vg_read_with_pv_and_lv(): allocated LE of LV" creating "/etc/lvmtab" and "/etc/lvmtab.d"

OK, create a new vg and import?
vgcreate gives:
vgcreate -- ERROR: "/etc/lvmtab" doesn't exist; please run vgscan
and pvscan gives:
pvscan -- reading all physical volumes (this may take a while...)
pvscan -- inactive PV "/dev/hda3"  is associated to an unknown VG (run vgscan)
pvscan -- inactive PV "/dev/hda4"  is associated to an unknown VG (run vgscan)
pvscan -- total: 2 [16.88 GB] / in use: 2 [16.88 GB] / in no VG: 0 [0]

Where do I go from here - vgcfgrestore? uuid_fixer? Even something really smelly!
Thanks,
    Bill
(Sorry if this comes over a bit garbled, I'm posting using lynx, 'coz
pine's somewhere on /dev/hda4 ...)