Considering that the sole purpose of Deja Dup is to backup and one of the main selling points of a WD My Cloud NAS drive is as a place to store your backup; it is surprisingly difficult to do it in a seamless way on Ubuntu. By seamless I mean it happens in the background without you having to think about it.
Here is how I did it on Ubuntu 18.04 LTS with a WD My Cloud Mirror:
1. Create a share on WD My Cloud
Using the My Cloud interface create a ‘share’ on the WD My Cloud (see About Shares in the User Manual), ensure NFS is set to on and give the share a relevant name (e.g. Backup).
2. Create a local folder to act as mount point
Using the terminal create a folder on the computer you are backing up:
sudo mkdir /mnt/Backup. This is the folder you will mount the NAS drive too; you can create this folder anywhere you consider sensible.
3. Open fstab file
Using the terminal open your fstab file using
gksudo gedit /etc/fstab. This fstab file determines what drive Ubuntu mounts at startup.
4. Add new line to fstab file
Create a new line at the end of the fstab file and; where ‘wdmycloudmirror’ is your device name (see Configuring Settings in the User Manual), the first
Backup is the share you created at Step 1 and
/mnt/Backup is the folder you created at Step 2; add the following
wdmycloudmirror.local:/nfs/Backup /mnt/Backup nfs defaults 0 0
5. Create /etc/network/if-up.d/fstab file
Using the terminal create a file with the command
gksudo gedit /etc/network/if-up.d/fstab.
6. Edit /etc/network/if-up.d/fstab file
Copy and paste the following text to the file created at Step 5:
#!/bin/sh mount -a
7. Make /etc/network/if-up.d/fstab file executable
Make the file executable:
sudo chmod +x /etc/network/if-up.d/fstab.
Reboot. The drive should mount on startup.
9. Select backup options in Deja Dup
Open Backups on Ubuntu (although the name is Deja Dup, it is not known as that) and select ‘Storage location’. For storage location select ‘Local Folder’ and then choose /mnt/Backup or whatever folder you chose at Step 2.
10. Back up
Select ‘Back Up Now’ from Overview and set up scheduling.
These instruction borrow heavily from an answer on Ubuntu Forums, which was helpfully reposted on Ask Ubuntu.