How to Set Up Snapshot Replication on a Synology NAS

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  • Post last modified:November 30, 2023
  • Post category:Synology
  • Reading time:11 mins read

Today we are going to take a look at how to set up snapshot replication on a Synology NAS!

First, you’re going to need to make sure that you already configured Snapshots. You can learn how to do that here if you haven’t set that up already. Snapshots are something that everyone should be using, regardless of the situation.

However, there is a limitation in that you must be using the BTRFS file system to use snapshots. Snapshot replication takes things a step further and allows you to replicate a folder with snapshots to a different Synology NAS (or locally).

You must confirm that the source and destination NAS are both using the BTRFS file system to proceed.

How to Set Up Snapshot Replication on a Synology NAS

1. Open Snapshot Replication and select Replication, then select Create.

how to set up snapshot replication on a synology nas - shared folder replication

2. You will be shown a screen with a few disclaimers. Select Next to proceed.

synology nas snapshot replication - replication task settings

3. At this screen, you will have the option to create this replication task locally or remotely. There are benefits to doing it locally, though ideally it will be done on a separate Synology NAS. In this tutorial, we will focus on using a second NAS, so I will be selecting Remote.

synology nas snapshot replication - connecting to a local or remote server

4. Enter in the IP Address, Username, and Password. Select Use encrypted connection, and then select Advanced Settings.

synology nas snapshot replication - connecting to the destination server

5. Ensure that you select the correct HTTPS port for DSM on the destination server. You will also have to ensure that the DSM port and shared folder port (5566) are allowed if you’re using Synology’s Firewall. This will have to be done on both, the source and destination servers.

synology nas snapshot replication - connecting to the destination server with the correct ports

6. When you select Next, the connection will be tested. If it’s not successful, you will be informed that the connection cannot be established, and you’ll be told why. Ensure that your firewall rules are properly created and the destination server can be reached!

failed to connect to destination error

7. Select the volume you’d like to use on the destination server and select Next.

the volume to use on the destination server

8. Select the folders that you’d like to replicate and select Next.

9. Select Send the initial copy over the network and select Next. This will send the data directly to the destination NAS and will sync as soon as the task is finished (as long as you keep the checkbox enabled).

data that will be sent over the network

10. The replication schedule can now be configured. This will be dependent on when you want the task running and can even specify transfer windows if you’d like.

schedule of when the replication task should run

11. The retention policy will determine how many snapshots will be retained. This is another option that’s going to be user-specific, but the advanced retention policy will allow you to define multiple policies.

retention settings for the destination server

12. Modify the advanced settings to how you’d like. If you’d like all snapshots taken to be sent to the destination server, you can enable the first checkbox. If not, you can proceed.

advanced settings for the replication server

13. Select Apply and the snapshots will start to sync! You will see on the destination server that a folder has been created which contains the files of the source folder.

Switchover/Failover with Snapshot Replication

The destination server will now contain a folder with the exact same files that are on the local NAS device, along with any snapshots that were sent. However, the files will be read-only

Please keep in mind that you can simply download the files on the destination NAS at any time if you don’t want to conduct a switchover/failover. The situation will determine if the steps below are necessary. 


A switchover will simply switch the source and destination Synology NAS’s, but will sync the data from source to destination before the switch finishes. To conduct a switchover (on the source NAS), select Recovery, find the folder, select Action then Switchover, and finally select Switchover.

switchover process where the nas will automatically switch over to the other synology nas

If the data on the source Synology NAS has been compromised, you most likely want to use the failover option below. If you indirectly complete a switchover when a failover should have been used, you can navigate to the destination NAS (now source), restore a snapshot, then sync the replication task.

The data on your initial source NAS will now be restored! This process will sync the data from the source NAS to the destination NAS before switching over. If the data on your source NAS has been compromised, look at the failover option below.


Generally, you’re only going to be implementing this in a catastrophic event. Meaning the data on your local NAS has been compromised, all snapshots are unrecoverable, and you need to sync the data from your destination NAS to your source NAS. This process will failover to the replication destination where your data (should) be secure.

You can conduct a failover from the destination NAS if the source data is compromised. To conduct this, login to the destination NAS, select the Recovery tab in the Snapshot Replication tool, then select Action -> Force Failover. This will change the source and destination, but will not sync the data from the source to the destination. 

failover where the nas will fail over the other second nas if needed

After the failover has been completed, you can conduct a Re-protect, which will sync the correct data from one NAS to the other.

re-protecting a synology nas after it has failed

The switchover/failover steps are a little confusing, so if you’ve made it this far (and actually need to perform this), I highly suggest watching the video above as it’s explained, and both recovery options are demonstrated.

Conclusion & Final Thoughts

This tutorial looked at how to set up Snapshot Replication on a Synology NAS. Snapshot recovery is a way to back up your NAS incrementally, that’s different than Hyper Backup.

Hyper Backup is significantly more portable (and can be encrypted). I just want to make clear that they’re both tools that can be used, but your needs might dictate which is better than the other.

Thanks for checking out the tutorial on how to set up Snapshot Replication on a Synology NAS! If you have any questions on how to set up Snapshot Replication on a Synology NAS, please leave a comment! You can also leave a comment on the YouTube video above if you have any questions!

Please share if this helped you!


Frank is an IT professional with over 13 years experience and is the creator of WunderTech. He started his home lab in 2018 and is passionate about educating people on NAS, Docker, virtualization, firewalls, and self-hosted apps through his experiences as an avid home lab enthusiast. Frank holds a Bachelor's of Science degree in Computer Information Systems and a Master of Business Administration (MBA).

This Post Has 6 Comments

  1. Steven Williams

    thanks for this.

    I cannot for the life of me connect my nas (1621+ DSM 7 to the replication server (412+) DSM 6
    Both have DSM Login set to same port number
    Both have Firewall open for DSM and 5566
    Using Advanced setting made sure Source was pointed to Destination DSM Port Number

    But I just get bounded with ‘unable to connect’

    Do I need to open those ports on both routers???

    I can sucessfully connect and hyperbackup to the destination maching via address

    Stuck! Any help appreciated!

    1. WunderTech

      If they are on different networks, then yes, both ports will need to be opened on each router. However, I would really suggest that you use Synology’s Firewall to limit access on those ports to only local traffic and the opposite external IP address (for security purposes).

  2. steve

    thanks for the reply! You are an absolute star.
    The destination was is indeed offsite. After opening ports on routers I can now connect to the destination via a DDNs host name. It accepts the connection from the host, and asks for 2FA, which it accepts – but then says it failed to connect to server.So close but no banana.
    Also creating a firewall rule for destination server IP – is it’s managed by Synology DNS, would it not be subject to change? Hypervault is working perfectly between devices.

    1. WunderTech

      If you are using a DDNS hostname and it’s configured properly, then you are good. It should update any time the IP address changes. As for the 2FA issue – that’s a tough one. It should just work (as I’ve used it and done exactly what you’re trying to do and it accepts the number). I wish I had any input to provide, but if it never works, it might be best to reach out to Synology support.

  3. Gillou

    I have ds918+ Performing replication using snapshot replication on a ds1812+, both on dsm6 on a local network.
    If I upgrade ds918+ in dsm7 can you confirm that snapshot replication will still work on my secondary ds1812+ running dsm6 without any restriction ?

    1. WunderTech

      I unfortunately cannot – the best thing to do in this case would be to reach out to Synology support and see if they can verify that everything will work as expected.

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