This is actually not an easy fix, though it might be doable.  The problem lies with the fact that we don't know what device to clean up with just "uninstall" in the kernel commandline.  We do most of the cleanup in dracut with detecting where HostVG, but the cleaning of the mbr is done in ovirt-early.  

There are a couple of approaches that we could take, though both are speculative until I try to implement them

1.  cleanup mbr in dracut as well -- not easy.  I think we would need to include sfdisk in dracut to determine the right places on the disk to cleanup

2.  We *could* leave the HostVG volume group after we're done with dracut and cleaning up all the LV's.  Then we can wipe HostVG, PVs and mbr from disks in ovirt-early.  Note:  this is a radical change since we don't individually clean up LVs now.  

3.  pass information to the running system from dracut -- I don't even know if this is technically possible, but it would solve the problem if we could.

There may be others, but none that I can think of at the moment.

Alan, any thoughts on the above?

Created attachment 523431 [details]
Patch

After discussion with Alan, we decided that we can detect the disk that contains Root and RootBackup partitions and wipe that.

Check this issue with RHEV-H 6.2-20111010.2 build. It is not fixed, After uninstall in kernel cmd, it didn't remove Rootbackup/Root. and it still can be bootable.

#pvs
#lvs
No volume groups found
#vgs
No volume groups found
#findfs LABEL=Root
/dev/sda2
#findfs LABEL=RootBackup
/dev/sda1

Assigned it.

Called the wrong function, so it wasn't wiping any disks.

diff --git a/scripts/ovirt-early b/scripts/ovirt-early
index 28ebd05..6c22054 100755
--- a/scripts/ovirt-early
+++ b/scripts/ovirt-early
@@ -679,7 +679,7 @@ start_ovirt_early () {
         oldIFS=$IFS
         log "Found uninstall arg, wiping mbr from init disks"
         IFS=$SEP
-        for init_disk in $init $init_app $(get_boot_disk); do
+        for init_disk in $init $init_app $(get_boot_device); do
             echo "Wiping $init_disk"
             wipe_mbr "$init_disk"
         done

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1783.html