macOS: proper Time Machine support (i.e. over SMB)



I have recently bought a My Cloud Home Duo after having received confirmation from WD that it supported macOS High Sierra.

To my surprise, I found that Time Machine (abridged TM afterwards) backups are still mounted through Apple Filing Protocol, which has been superseded by SMB2 as the default protocol for sharing files starting with OS X Mavericks (10.9). WD must be using some sort of hacking to use AFP for Time Machine because Apple said that, when using APFS (which is mandatory with SSD under High Sierra), TM is only supported over SMB Shares (See:

APFS and Time Machine
You don’t need to change any Time Machine settings to back up APFS-formatted disks.
Any Time Machine share points must be shared over SMB instead of AFP.

Actually, TM over SMB is supported since Sierra (10.12) and Apple published a specification on 13 September 2016 (see: To my understanding, it specifies extensions to the SMB protocol to ensure reliable backups.

WD introduced TM over SMB on other products, see for example My Cloud OS since last September, so it seems that WS masters the implementation.

Finally, Samba 4.8 released on 13 March 2018 is said to support TM (over SMB). Samba is an open sourced implementation of SMB that it used by WD and others.

Looking into the GPL softwares used by WS, My Cloud Home seems to keep relying on Netatalk to run AFP file sharing and which to my knowledge is only faking the support of the required features to ensure reliable Time Machine backups.

Apple says APFS hard drive requires SMB to run Time Machine today, so it will be in the future. I would like WD to confirm that it intends to support TM over SMB soon for My Cloud Home (Duo) (and that in the mean time, Time Machine Wi-Fi backups are reliable with My Cloud Home).





I’ve just found out (thanks to WD support) that it is possible to enable TM over SMB with the My Cloud Home. See:

It requires to use the Terminal.

It would be great that TM over SMB is advertised on Bonjour, meaning as easy and transparent as it is with AFP currently.




I did not succeed to make it work yet…

arp -a
mycloud-111308.home (192.168.1.XX) at XX:XX:XX:XX:XX:XX on en0 ifscope [ethernet]
sudo tmutil setdestination smb://guest:guest@192.168.1.XX/TimeMachineBackup
Failed to mount smb://192.168.1.XX/TimeMachineBackup (error 22)
The backup destination could not be set.

When I manually mount via SMB in the Finder, only the “Public” folder is being shown, not the TimeMachineBackup.


Well now WD support now says that in the end My Cloud Home does not support Time Machine over SMB.

The knowledge base article has been update here: and now reads

Time Machine Backup over SMB to a My Cloud Home is Not Supported.

Which is a shame since AFP is deprecated since macOS Mavericks and won’t likely be supported for Time Machine in the near future.

So far, WDC is not saying that it will be supported in the future (despite it is on other My Cloud products). Money unwell spent if it stays like this.


Well, what got to be be, I’m getting my first errors for unreliable backups from Time Machine that leads to losing former incremental backups and redoing a full backup… My Cloud Home would definitely benefit from a true implementation of Time Machine over SMB… it’s long overdue.

My Cloud Home Duo on Mac High Sierra - slow but now working!

And here we go again. New unreliable backup, gonna have to redo the whole things. What’s the point of backing up on My Cloud Home if backups turn out to be unreliable every 4 months?

Any plan to improve this in the near future?