Knowledge Center

Shared Folder Sync

The Shared Folder Sync service allows users to sync shared folders from one Synology NAS device (the source) to other Synology NAS devices (the destination) within the LAN or over the Internet.

Shared Folder Sync will perform a full sync of the selected shared folders for the first time. Afterwards, only modified files will be synced. Files that have been removed from the source will also be removed from the destination.

Note:

  • Shared Folder Sync is a one-way sync solution, syncing the files from the source to the destination. For a 2-way sync solution, please use Synology Drive ShareSync.
  • If on the destination exists a shared folder with the same name (e.g., SharedFolder) as the shared folder on the source, a new folder with a numbered name (e.g., SharedFolder_1) will be created at the destination when syncing.
  • If on the destination exists no shared folders with the same name as the shared folder on the source, a new folder with the same name will be created on the first volume available.
  • By default, no users will have access permission to the shared folder synced to and existing on the destination. Please contact the destination admin to enable access permissions.

Enabling the Service

To enable Shared Folder Sync:

You have to enable the service on the destination Synology NAS first.

  1. Go to Control Panel > File Services > rsync.
  2. Tick the Enable rsync service checkbox to enable the Shared Folder Sync service.
  3. Click Apply.

To unlink shared folders from destination Synology NAS:

If different sources simultaneously sync an identical shared folder to one destination Synology NAS, there will be a conflict. You will need to unlink the shared folder on the source side before another source can sync its folder to the destination.

  1. Sign in to the destination Synology NAS and go to Control Panel > Shared Folder Sync > Connection List.
  2. Select the conflicting connection from a source Synology NAS, and then click Unlink to remove it.

Now another source can sync the shared folder to the destination Synology NAS.

Managing Sync Tasks

To create a sync task:

  1. Sign in to the source Synology NAS and go to Control Panel > Shared Folder Sync > Task List.
  2. Click Create.
  3. Enter a name for the task.
  4. Select the shared folder or shared folders you want to sync to the destination.
  5. Specify the destination Synology NAS and select the sync options that suit your needs:
    • Customize SSH encryption port for encrypted shared folder sync: Specify the desired encryption port for SSH transfer encryption.
    • Enable SSH transfer encryption: Encrypt data during transfer. This provides better security, while non-encrypted transfer provides better performance. You can choose according to your needs.
    • Enable transfer compression: Compress data during transfer. It will save network bandwidth but increase CPU loading.
    • Enable block-level synchronization: Transfer only differential data instead of whole files. It will save network bandwidth but increase CPU loading.
  6. When prompted, select any of the following options to decide when to sync from the source to the destination:
    • Run sync on modification: Run the sync task immediately once any changes occur at the source shared folder.
    • Run sync manually: Run the sync task manually from the source shared folder.
    • Advanced schedule: Click Schedule Plan to specify when to perform the sync task.
  7. Click Apply. Now you can see the sync task on the task list, which will be performed according to the specified schedule.

To manage a sync task:

  1. On the source Synology NAS, go to Control Panel > Shared Folder Sync, click Task List, and select the desired task.
  2. Do any of the following:
    • Click Edit to edit the task.
    • Click Delete to delete the task.
    • Click Sync Now to perform the task right away if the sync task is not in progress.
    • Click Cancel to stop the ongoing task if the sync task is in progress.

      • Note:

      If the schedule for a sync task is set as Run sync on modification, clicking Cancel would stop the ongoing sync task. However, if any changes are made to the contents of any shared folders monitored by the sync task, Shared Folder Sync would resume the task.

    • Click Full Sync to sync all data. Shared Folder Sync will run a full sync for the first time, and only sync the modified parts after the first sync. Clicking this button can help you manually sync all data again.
    • Btrfs (Peta Volume) file system does not support encrypted shared folders.

More Information

  1. Task name must be of 1 to 32 Unicode characters and must not contain the following characters:
    ! " # $ % & ' ( ) * + , / : ; < = > ? @ [ ] \ ^ ` { } | ~
  2. If you sync shared folders from ext4 to ext3 file system, you may encounter errors when the task contains over 32,000 folders.
  3. If the shared folders in the destination Synology NAS have been synced with other Synology NAS before, Shared Folder Sync will perform a full sync for the task.
  4. To perform Shared Folder Sync tasks, you need the admin privilege of the destination Synology NAS. Either you have its admin account's password, or you are in its administrative group.
  5. When syncing to the destination Synology NAS over the Internet, you can enter the server name by its external IP address or its hostname. However, if you choose to enter its hostname, the name must be in FQDN (Fully Qualified Domain Name) format, like "www.synology.com".
  6. For port-forwarding, Shared Folder Sync uses port 22 for encrypted transfer and port 873 for unencrypted transfer.
  7. External storage devices are not supported by Shared Folder Sync.
  8. When the Shared Folder Sync task runs, the encrypted shared folders at the destination will be automatically mounted; however, to access the data inside, you must mount the encrypted shared folders at the destination first.
  9. Scheduled Shared Folder Sync will not run at the specified time if no changes have been made to the selected shared folder.
  10. For best performance, we suggest each sync task include less than 200 shared folders.
  11. The User Home function will be disabled on the destination Synology NAS if the homes shared folder is synced from the source Synology NAS to the destination Synology NAS.
  12. For models with package architectures 88f628x or Qoriq, you can sync up to 100,000 shared folders (including subfolders) using Shared Folder Sync. Please refer to this FAQ to learn about the package architecture your Synology NAS uses.
  13. Shared Folder Sync can back up Windows ACL settings when the destination file system is ext4 or Btrfs.
    Note: Data and Windows ACL settings stored on Synology NAS cannot be synced to EDS14.
  14. Shared Folder Sync will fail if you are syncing to a destination server which shares the same name as your Synology NAS.
  15. Advanced Shared Folder Permissions at the source will not be synced to the destination. Furthermore, a read-only rule for administrators group will be created at the destination.
  16. To ensure the functionality of Shared Folder Sync, the system automatically overwrites the privilege settings in Control Panel > Shared Folder > Edit > Advanced Permissions > Advanced Share Permissions every time a sync task is carried out. The privilege settings for the current user account on the destination will be changed to Read Only. All other users on the destination that have Read Only privilege will have their privilege revoked (unticked).
  17. Shared Folder Sync does not sync the #recycle folder, except when it is inside an encrypted folder on the source.

Enabling the Service
Managing Sync Tasks