Description of problem:

If a software raid device is in degraded state at the time of the "rear mkrescue" creation (e.g. a device has been removed from a RAID1 array), the disk layout restoration will fail with following error seen in the log:

mdadm --create /dev/md127 --force --metadata=1.2 --level=raid1 --raid-devices=2 --uuid=a0fc5637:fdf5dafa:a345e010:83293548 --name=boot /dev/sdb1
+++ echo Y
mdadm: You haven't given enough devices (real or missing) to create this array


This is indeed due to the missing device (/dev/mapper/mpatha1)


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

rear-2.00-3.el7_4.x86_64


How reproducible:

ALWAYS


Steps to Reproduce:
1. Set up a software raid with 2 devices in RAID1
2. Remove one of the device (/dev/sda1)
3. Create rear rescue image
4. Try restoring the disk layout

Actual results:

initramfs's /var/lib/rear/layout/disklayout.conf will contain:

raid /dev/md127 metadata=1.2 level=raid1 raid-devices=2 uuid=a0fc5637:fdf5dafa:a345e010:83293548 name=boot devices=/dev/sdb1
...

leading to mdadm complaining and aborting.


Additional info:

Issue to be created in Upstream as well