Backup RHEV/RHV/ovirt disk image to external drive

Login to RHV/RHEV/ovirt administrator interface

Search for your VM, lets say I want to search for windows VM

Right click on the VM name, and choose 'Create Snapshot'

Give a proper name, and tick "Save Memory" if you want to save current state of memory as well. Please be warned, that by choosing "Save Memory", the VM will be paused while the snapshooting is in progress. 

If you check the Snapshots tab, the status of the snapshot will be Locked, and the VM will be paused

Once completed, the status will be changed to Ok

Now, open a terminal inside the rhev machine, and search for the disk image snapshot by running below command:

# virsh -r dumpxml windows | grep "source file"

Your newly created snapshot is on the last line of the above command. Copy the file location, and put it into your external drive

# cp /rhev/data-center/00000002-0002-0002-0002-00000000035d/747b7d84-68d5-4436-98f5-baeec68381e1/images/8af6c761-94ac-4adb-bf33-f009e3dd3dc7/../8af6c761-94ac-4adb-bf33-f009e3dd3dc7/../8af6c761-94ac-4adb-bf33-f009e3dd3dc7/../8af6c761-94ac-4adb-bf33-f009e3dd3dc7/../8af6c761-94ac-4adb-bf33-f009e3dd3dc7/e42c8e85-9566-4953-b881-70c7ce97de0b /mnt/my_external_drive/windows-snapshot-20181219.raw

If you want a different format, use qemu-img command to change it. For example, you require this image to be vmware compatible

# qemu-img -f raw -O vmdk /mnt/my_external_drive/windows-snapshot-20181219.raw /mnt/my_external_drive/windows-snapshot-20181219.vmdk

Adding new virtual hard disk to existing RHV virtual machine

Login to your RHV/RHEV/ovirt console

Enter your administrator username and password



Once inside, search for your VM name

Scroll down, and choose Disk tab

Add details of your new virtual hard disk and click OK once done.



Make sure that your newly created disk is listed in the Disk tab

Login to your vm, and run lsblk to check your newly created disk
# lsblk 
NAME              MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
...
vdc               252:32   0   200G  0 disk 

Create partition on the new disk

# cfdisk /dev/vdc

Choose New --> Primary --> Set size --> Write --> answer 'yes' --> Quit

Run lsblk again to check if your partition is successfully created 

# lsblk 
NAME              MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
...
vdc               252:32   0   200G  0 disk 
└─vdc1            252:33   0   200G  0 part 



Make filesystem for your partition, in this case I want an ext4 partition
# mkfs.ext4 /dev/vdc1 
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
...
Writing superblocks and filesystem accounting information: done   

Once done, you can mount your partition wherever you want
# mount /dev/vdc1 /mnt
# df -Th /mnt/
Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/vdc1      ext4  197G   61M  187G   1% /mnt

Score!!