Description of problem:

When a system contains LVM Thin volumes (something supported since RHEL6.4), ReaR recovery fails with the following error:

lvm vgcfgrestore -f /var/lib/rear/layout/lvm/rhel.cfg vgroot
Consider using option --force to restore Volume Group rhel with thin volumes.
Restore failed.

Trying to use the "--force" option by modifying /var/lib/rear/layout/diskrestore.sh doesn't help.
It then fails checking the Thin volume, because /usr/sbin/thin_check is not part of the ReaR image by default.

Finally, after adding /usr/sbin/thin_check to the ReaR image (using REQUIRED_PROGS variable), it still fails when trying to make the VG available:

lvm vgchange --available y rhel
  WARNING: Failed to connect to lvmetad. Falling back to device scanning.
  Monitoring rhel/pool00 failed.
  device-mapper: reload ioctl on  (252:5) failed: No data available
  2 logical volume(s) in volume group "rhel" now active

I've then stopped investigation at this step.

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

rear-2.00-2.el7.x86_64


How reproducible:

ALWAYS


Steps to Reproduce:
1. Install a VM, selecting "LVM Thin Provisioning" instead of "LVM" for root LV
2. Create ReaR rescue image
3. Try restoring the disk layout