Synchronising across 2 NAS devices


A friend and I are adding files to our local folder on the NAS. He has his own NAS and I have my own NAS. If I add a file to my folder, I want it to automatically synchronise with his folder, and when he adds a file to his folder, I want it to automatically synchronise with my folder.

I was wondering if this was possible, reason we do it like this is because accessing each others’ folder over internet is going too slowly so we want to have the same files and folder structure, on our local own local NAS but when someone adds to their own folder, that the other persons’ folder synchronises the files added or removed.


Have you read the User Manual?
My Cloud OS 5 Online User Manual (

Have you checked the Knowledge Base?

One has a number of options if both NAS devices are on the same local network. From using software on a computer to compare each folder location and synchronize between the two NAS devices to seeing if GoodSync may synchronize between supported NAS devices to using Rsync (and CRON) scripting to copy files from one location to another.

It will likely come down to the specific NAS models one is using and what options and features each support. Some of the more full featured NAS devices, like those from Synology or Qnap may have apps/modules that will sync files with another NAS device. The OS5 My Cloud does have an option for backing up to another supported OS5 My Cloud.

My Cloud OS 5: Remote Backups

GoodSync for WD NAS Users

GoodSync Free and Premium for WD My Cloud

Rsync to Synology Drive

Free File Sync

They are not both on the same local network.

The NAS boxes being on different networks is an important detail not previously mentioned. If one is trying to copy or sync data from their local NAS to a remote network NAS it complicates things. Without knowing what specific NAS devices that one is trying to copy data between; we can only give general answers or suggestions.

If one is using a My Cloud (not My Cloud Home) device running the OS5 (v5.x) firmware then look into Goodsync that was previously mentioned, or see the previously provided WD Support Knowledgebase Article on Remote Backups.

Like indicated before, it really comes down to what specific NAS models/brands one is using as to how one may try and copy data between them.

Both of us are using the same MyCloud Ultra and I’ve been looking into Goodsync, I’m not sure yet how to correctly set it up, but I think I need to just sync his NAS folder with my NAS folder and then when he makes changes, it also changes in my NAS folder and vice versa.

The fundamental issue is the NAS units are on different networks.

Option 1: put them on the same network. You can do this via a VPN between the networks. Easy Peasy - if you had VPN client software running on the NAS - which I don’t know about.

The NAS is running lobotomized Linux. You would have to bypass the WD GUI and install/run a VPN client on a NAS. On the other network; you need a vpn server. Often, cheap routers can run vpn server software.

(There is a bunch more to this - but you get the gist)

Option two: run VPN client on a pc, and use the NAS as a network drive on the PC. Advantage: probably easier to setup. Disadvantage: requires pc to run

Option 3: look into different NAS vendor who views this as a valid use case. (wD does not)

Option 4: Dropbox

I’ve tried everything so far yes, I was able to set it up once after hours of trying but now I messed something up and I can’t set it up again in the way it was before

I see you tried Good Sync.
GoodSync backup service enables you to backup data from your computer to a WD device, and from your WD device to a remote location including other computers, other WD devices, or cloud storage.

Software and Firmware Downloads | WD Support (

GoodSync Support Page

I think the VPN option sounds good. The strange thing is, I was able to do this in the past!
Setup looked like this:
NAS was connected to my home-WIFI
When I was in the office, I was able to access it in “Finder”, I was able to drag and drop files in the NAS even though I was on a different network (Office network = not same as home network → different address)

My friend in the Netherlands, was ALSO able to access my NAS in his finder, was also able to drag and drop files in his finder and update the folder.

All this was possible without a VPN, so I’m confused as to why it’s not possible anymore and how no-one is able to tell me what I should do to replicate the steps. In fact I made a PDF in the time, on how to replicate those steps, but the steps no longer seem to work.

So it sounds like something changed in your network configuration.

Did an upgrade from OS3 to OS5 occur?

If you are accessing without a vpn that implies you are accessing the NAS via open ports on your router. (i.e. navigating to wan.ip.add.ress:“Port assignment”). This is insecure as all get-out. . .but will work. If you are using OS/5, the “ports” that the NAS box listens to (used to be 8445 IIRC) has changed. No idea how OS/5 does port assignments.

If the change to OS/5 didn’t occur. . . then did something change with your routers? Are you sure of the WAN ip address of your router?

These issues are what drove me to using a vpn, with DDNS access.

  • consistent signon protocol to find my router on the WAN
  • Secure connection to my system from whatever dodgy hotel or airport I am dialing in from.
  • Not as reliant on NAS security as sole protection for my system. (i.e. the VPN connection through the router is a second firewall)

WD has a Knowledge Base Article covering OS5 port usage.

My Cloud OS 5: Port Usage and Assignments

Dang. I never found that when I was trying to figure out OS/5.

Feels like LOTS of open ports for all sorts of things. Is there a handy chart like that for OS/3? I would be curious on that.

For OS 3:
My Cloud Port Usage and Assignments

How to Enable Port Forwarding on a Network Router with a My Cloud

@bennor: Thanks for finding those. . . very interesting to me.