Shared Folder Sync
Shared Folder Sync is a one-way syncing solution that 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.
The first time a sync task runs, Shared Folder Sync will perform a full sync of the selected shared folders. Afterwards, only modified files will be synced. Files that have been removed from the source will also be removed from the destination.
Note:
- By default, no users have access permission to the synced shared folder on the destination. Please contact an admin on the destination Synology NAS to enable access permissions.
- Naming of the synced shared folder on the destination Synology NAS:
- If the destination does not have a folder with the same name as the source (e.g., "SharedFolder"), a new folder with the same name ("SharedFolder") will be automatically created on the first available volume.
- If the destination already has a folder with the same name as the source (e.g., both named "SharedFolder"), the original folder on the destination will be renamed by appending an underscore and a number to the original name ("SharedFolder_1"). Another folder ("SharedFolder") will be created on the destination. Contents in the source folder ("SharedFolder") will be synced to the newly created folder ("SharedFolder") on the destination.
- For 2-way syncing solution, refer to Synology Drive ShareSync.
Required Settings
To ensure your sync tasks can be set up successfully, configure the following settings first.
- Make sure the server names of the source and destination Synology NAS are different. If they are the same, you can modify the server name on either Synology NAS at Control Panel > Network > General > Server name.
- To sync over the Internet, configure port forwarding rules for Shared Folder Sync. The default ports are port 22 for encrypted transfers and 873 for unencrypted transfers.
Enabling the Service
To enable Shared Folder Sync:
You must enable the service on the destination Synology NAS first.
- Go to Control Panel > File Services > rsync.
- Tick Enable rsync service.
- Click Apply.
Syncing From Multiple Sources
If you want to sync multiple source folders to the same destination folder, make sure all source folders are named differently. Rename one of the source folders to avoid syncing conflict.
Syncing to the Same Destination Folder From a New Source
If you are syncing multiple source folders with the same name to the same destination folder, conflicts will occur. You must unlink the original source folder first. Unlinking the source folder will not remove data from the destination folder.
- Sign in to the destination Synology NAS and go to Control Panel > File Services > Advanced > Shared Folder Sync > Connection List.
- Select the conflicting connection from a source Synology NAS, and then click Unlink to remove it.
After unlinking the original source folder, create a new sync task with the new source folder and perform a full sync.
Managing Sync Tasks
To create a sync task:
- Sign in to the source Synology NAS and go to Control Panel > File Services > Advanced > Shared Folder Sync > Task List.
- Click Create.
- Enter a name for the task and click Next.
- The task name must be of 1 to 32 Unicode characters and must not contain the following characters:
! " # $ % & ' ( ) * + , / : ; < = > ? @ [ ] \ ^ ` { } | ~
- The task name must be of 1 to 32 Unicode characters and must not contain the following characters:
- Select the shared folder or shared folders you want to sync to the destination. Tick to acknowledge the disclaimer and click Next.
- For best performance, we recommend including no more than 200 shared folders for each sync task.
- Enter the IP address/server name of the destination Synology NAS and sign in with the credentials of a user belonging to the administrators group.
- When syncing over the Internet, you can enter the external IP address or server name of the destination Synology NAS. However, if you choose to enter the server name, the name must be in FQDN (Fully Qualified Domain Name) format, such as "www.synology.com".
- Select the sync options that suit your needs, and click Next.
- Customize SSH encryption port for encrypted shared folder sync: You can specify the desired encryption port for SSH transfer encryption.
- Enable SSH transfer encryption: This option encrypts data during transfer. While encrypted transfer provides better security, non-encrypted transfer provides better performance. You can choose according to your needs.
- Enable transfer compression: This option compresses data during transfer. It will save network bandwidth but increase CPU loading.
- Enable block-level synchronization: Enable this option to transfer only differential data instead of whole files. It will save network bandwidth but increase CPU loading.
- Sync remote mounted folders: Synchronize remote mounted folders, including CIFS shared folders and NFS shared folders.
- Select when to sync from the source to the destination and click Next.
- 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 run the sync task. Scheduled tasks will not run at the specified time if no changes have been made to the selected shared folder.
- Review your task settings and click Done. The sync task will appear on the Task List and will run according to the specified schedule.
To manage a sync task:
- On the source Synology NAS, go to Control Panel > File Services > Advanced > Shared Folder Sync > Task List, and select the desired task.
- Do any of the following:
- Click Edit to edit the task.
- Click Delete to delete the task.
- Click Cancel to stop the ongoing task if the sync task is in progress. Please note that clicking Cancel for a sync task with Run sync on modification will 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 Sync Now to perform the task right away if the sync task is not in progress.
- 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 allows you to manually sync all data again.
Note:
- File systems and storage:
- When syncing shared folders from an ext4 to an ext3 file system, errors may occur if the task contains over 32,000 folders and subfolders.
- Shared Folder Sync syncs Windows ACL settings when the destination file system is ext4 or Btrfs.
- Shared Folder Sync does not support external storage devices.
- Btrfs (Peta Volume) file system does not support encrypted shared folders.
- Advanced Share Permissions at Control Panel > Shared Folder > Edit > Advanced Permissions > Advanced Share Permissions:
- Advanced Share Permissions at the source will not be synced to the destination.
- To ensure the functionality of Shared Folder Sync, a read-only rule for administrators group will be created at the destination. Additionally, the first time a sync task is carried out, the system changes the Advanced Shared Folder Permissions of the current user account on the destination to Read Only. The privilege settings will not be changed in subsequent syncing.
- Shared folders:
- If the shared folders in the destination have been synced with other Synology NAS before, Shared Folder Sync will perform a full sync for the task.
- If a task includes encrypted shared folders, the folders will be automatically mounted at the destination when the task runs. However, to access the data inside, you must mount the encrypted shared folders at the destination first.
- Shared Folder Sync does not sync the #recycle folder, except when it is inside an encrypted folder on the source.
- Shared Folder Sync cannot detect modifications in the Docker shared folder. Thus, this folder cannot be automatically synced even if you selected the Run sync on modification option for this task.
- If the homes shared folder is included in a task, the User Home function will be disabled on the destination.
- Refer to this article to troubleshoot sync issues with error codes.