See the following with respect to backing up one single bay/single drive My Cloud unit to another single bay/single drive My Cloud unit in a remote location.
https://support.wdc.com/knowledgebase/answer.aspx?ID=13854
Officially you cannot “sync” one single bay/single drive My Cloud to another single bay/single drive My Cloud. Unofficially it may be possible to sync or backup one single bay My Cloud to another. However, most methods use SSH to modify the My Cloud firmware to do so. Use the forum search feature, magnifying glass icon upper right, as there are a number of past discussions on backing up one My Cloud to another remote My Cloud. Here is one such discussion:
https://community.wd.com/t/app-goodsync-for-wd-my-cloud-backup-and-file-synchronization/173984/
