+++ This bug was initially created as a clone of Bug #922593 +++

Description of problem:

When I install automatically the ovirt-node-2.6.1 iso that I built based on rhel6.3 repo  to our machine via pxe, I ran into the following error:

Starting ovirt-firstboot: Performing automatic disk partitioning
ERROR:ovirtnode.storage:HostVG/AppVG exists on a separate disk
ERROR:ovirtnode.storage:Manual Intervention required

It seems the auto install will stop if the "HostVG"  exists on the
disk on the machine.


In the emergency shell 

[root@mcptest ~]# cat /proc/cmdline
ksdevice=bootif text BOOTIF=eth0 firstboot storage_init=/dev/sda lang= storage_vol=50:1024:512:5:2048:-1 standalone hostname=mcptest
vga=791 rootpw=$1$cfm5kMmj$M1uknfs/8aSeZkJyf/NBC/
root=live:/ovirt-node-image-2.6.1-1.1.el6.iso ssh_pwauth=1
ks=http://9.181.129.219/cblr/svc/op/ks/system/62 rootfstype=auto ro
liveimg nomodeset check rootflags=loop crashkernel=512M-2G:64M,2G-:128M
elevator=deadline processor.max_cstate=1 install rhgb rd_NO_LUKS
rd_NO_MD rd_NO_DM


[root@mcptest ~]# pvs
   PV                                              VG     Fmt Attr
PSize PFree
   /dev/mapper/3600605b003b86620166a1ddb0bfa15b7p4 HostVG lvm2 a--
1.36t    0



We are installing it to the hard disk , and the previous installation is
RHEVH 6.3. During the installation, before performing the disk format, it checks that there is a existing HostVG on the disk, so it stops installing.


There is another question confused me. If I install rhev-hypervisor6-6.4-20130221 with ovirt-node-2.5.0 via pxe, which has same check_existing_hostvg code as what mentioned below,  I can install it successfully, in addition, I do some debug before run
_functions.OVIRT_VARS["OVIRT_ROOT_INSTALL"] = "y"
         if _functions.check_existing_hostvg("") or \
            _functions.check_existing_hostvg("","AppVG"):
             logger.error("HostVG/AppVG exists on a separate disk")
             logger.error("Manual Intervention required")
             return False
         if storage.perform_partitioning():
             return True

[root@mcptest ~]# pvs

I didn't got the HostVG information that got in ovirt-node-2.6.1 version. So I guess ovirt-node-2.5.0 does something about HostVG before check
but ovirt-node-2.6.1 doesn't.

 
Version-Release number of selected component (if applicable):
2.6.1

How reproducible:



Steps to Reproduce:
1. Build an ovirt-node-2.6.1 iso based on rhel6.3 repo
2. Install the iso to a bare mahcine via pxe, the parameters is like below:

sdevice=bootif text BOOTIF=eth0 firstboot storage_init=/dev/sda lang= storage_vol=50:1024:512:5:2048:-1 standalone hostname=mcptest
vga=791 rootpw=$1$cfm5kMmj$M1uknfs/8aSeZkJyf/NBC/
root=live:/ovirt-node-image-2.6.1-1.1.el6.iso ssh_pwauth=1
ks=http://9.181.129.219/cblr/svc/op/ks/system/62 rootfstype=auto ro
liveimg nomodeset check rootflags=loop crashkernel=512M-2G:64M,2G-:128M
elevator=deadline processor.max_cstate=1 install rhgb rd_NO_LUKS
rd_NO_MD rd_NO_DM

3. 
  
Actual results:

Starting ovirt-firstboot: Performing automatic disk partitioning
ERROR:ovirtnode.storage:HostVG/AppVG exists on a separate disk
ERROR:ovirtnode.storage:Manual Intervention required


Expected results:
Get installed successfully


Additional info: