Description of problem:
-----------------------
When RHVH node is rebooted, the boot/OS disk gets the multipath name.
During RHHI-V deployment from cockpit, the ansible task to blacklist the gluster brick devices, tries to perform 'multipath -F', which also tries to flush out the multipath names on the boot/OS disk, which eventually fails as the root filesystem is already active on boot disk

The quick solution here is not to perform, 'multipath -F' which tries to flush multipath names on all the disks. Reloading multipath ideally helps to activate the blacklisting of disk, and flushing the multipath disk names not required


Version-Release number of selected component (if applicable):
--------------------------------------------------------------
gluster-ansible-infra-1.0.4-8.el8rhgs

How reproducible:
------------------
Always

Steps to Reproduce:
-------------------
1. Install RHVH node, reboot the host post successful installation
2. Reboot the RHVH node, after the node comes up post successful first boot
3. Start RHHI-V deployment from web console (cockpit) with option 'blacklisting gluster devices' option enabled

Actual results:
----------------
RHHI-V deployment fails as the root/boot/OS disk has multipath name and that can't be flushed

Expected results:
-----------------
RHHI-V deployment should proceed though the root/OS disk has got multipath names

Additional info:
-----------------
<snip>
TASK [gluster.infra/roles/backend_setup : Flush all empty multipath devices] ***
fatal: [10.70.35.96]: FAILED! => {"changed": true, "cmd": "multipath -F", "delta": "0:00:00.055945", "end": "2020-05-04 08:11:26.787117", "msg": "non-zero return code", "rc": 1, "start": "2020-05-04 08:11:26.731172", "stderr": "May 04 08:11:26 | 0QEMU_QEMU_HARDDISK_drive-scsi0-0-0-0p2: map in use", "stderr_lines": ["May 04 08:11:26 | 0QEMU_QEMU_HARDDISK_drive-scsi0-0-0-0p2: map in use"], "stdout": "", "stdout_lines": []}
changed: [10.70.35.151]
changed: [10.70.35.136]
</snip>

In this case 10.70.35.96 node is rebooted and it had multipath name created for /dev/sda