I followed this guide here to backup mine 6TB My Cloud: http://community.wd.com/t/how-can-i-make-the-virgin-disk-imgae-of-my-cloud-2tb/91142/5
This command didnt worked for me:
Type this command to reset the firmware to a factory state
/usr/local/sbin/factoryRestore.sh noreformat
So in My Cloud dashboard settings, I did a fast restore instead. (is it same?)
Then I ran this command:
Type this command to backup all of the OS partitions etc
dd if=/dev/sda of=/DataVolume/shares/Public/mycloud.img bs=1M count=5000
Whick works to back up and mycloud.img was created in Public folder. The mycloud.img filesize was 5 120 000 kB.
I couldnt mount the img file in window 10, it said couldnt open or file is corrupt. So I used R.Linux window version instead and opened the img file, but here I didnt get any 396MB blank data, instead 5.45TB instead?
So did I all correct or wrong somewhere? The image file is fine or really corrupted, since couldnt mount it in win 10 and need R-Linux to mount it.