How to Migrate Data to a New UGREEN NAS

If your old NAS still works, leave its drives in place and transfer the files to your new UGREEN NAS over a wired local network. Rsync is the best starting point for Synology and other compatible NAS systems because you can copy the data in stages while keeping the source available.

Moving the drives themselves is a separate process. It applies only to an intact UGOS Pro storage pool transferred between compatible UGREEN NAS devices. Do not initialize Synology, QNAP, TrueNAS, Unraid, or other cross-brand arrays inside a UGREEN NAS.

Which NAS Migration Method Fits Your Setup?

If the working source does not support rsync, connect its SMB share as a network folder in the Files app and copy the data from there. An external drive can also provide temporary transfer storage, but it requires enough capacity and doubles the amount of copying.

This article covers NAS-to-NAS migration. For online services, use the workflows for moving Google Photos to UGREEN NAS or transferring and synchronizing Google Drive or Dropbox data.

Prepare Both NAS Devices Before Migrating

Migration reads a large portion of the source storage and writes the same amount to the destination. Check the backup, capacity, drive health, network, and account structure before starting.

Create an independent backup

The destination NAS is part of the migration, so it does not count as the safety copy for that operation. A failing source drive, incorrect filter, permission error, or accidental deletion can still affect the transfer.

Create or refresh an independent copy of irreplaceable data before moving drives or changing the source configuration. UGOS Pro can back up selected NAS folders to an external drive.

Do not physically migrate a degraded storage pool. Confirm that every pool and member drive reports a normal state. If a source drive is actively failing, prioritize copying irreplaceable files instead of forcing the array through repeated full reads.

Confirm usable destination capacity

Compare the used source capacity with the usable destination capacity. Raw drive capacity is not the amount available after RAID and system overhead.

For example, two 12TB drives provide 24TB of raw capacity. In RAID 1, the decimal usable capacity is exactly 12TB because the second drive mirrors the first.

Leave capacity for:

• Files created during migration
• Recycle Bin contents
• Retained file versions
• Application databases and thumbnails
• Snapshots
• Future library growth

If the destination does not provide enough bays, usable capacity, or network speed for the migrated workload, browse and filter NAS Storage models before committing the old system to the move.

Connect both systems with Ethernet

Connect both NAS devices to the same router or switch using Ethernet. A local transfer does not depend on your internet download speed.

The slowest part of the path determines sustained performance. Possible limits include the source drives, destination pool, network ports, switch, cables, encryption, and file workload.

Estimate the best-case duration with:

Transfer time in hours = decimal data size in MB ÷ sustained MB/s ÷ 3,600

For 10TB of data:

These figures assume sustained large-file transfers. Millions of small files can take considerably longer. Indexing, RAID maintenance, encryption, containers, and other active storage workloads also reduce transfer speed.

Record everything that must be rebuilt

File migration and system migration are separate jobs. Inventory the following before touching the source system:

• Shared folders
• Users and groups
• Folder permissions
• Backup and synchronization tasks
• Docker Compose files and persistent folders
• Virtual machines
• Application databases
• Media-server configuration
• Photo application metadata
• Client drive mappings
• Remote-access settings

For a UGREEN source NAS, open Control Panel > Update & Restore > Configuration Backup & Restore. Create a cloud configuration backup through your UGREEN Account or download a local .ugb file to your computer.

The configuration backup contains supported UGOS Pro settings. Docker containers, virtual machines, databases, and application data still need their own backups or exports.

How to Migrate from Synology or Another NAS with Rsync

Rsync can transfer the initial dataset and then send only files that were added or changed. This allows the old NAS to remain available during most of the migration.

Configure the destination UGREEN NAS to pull data from the source. That keeps the migration task under the control of the new system.

Enable rsync on the source NAS

For Synology DSM:

1. Sign in as an administrator.
2. Open Control Panel > File Services > rsync.
3. Enable the rsync service.
4. Create or select a migration account.
5. Give that account access to the required source folders.
6. Record the source NAS IP address and rsync port.
7. Enable encrypted transfer for a DSM user account.

Synology distinguishes DSM users from standalone rsync accounts. DSM users require encrypted transfer, while standalone rsync accounts use an unencrypted connection. Synology explains these account requirements in its official rsync documentation.

For another NAS brand, enable its rsync-compatible service and create a dedicated account with read access to the folders being migrated.

Keep rsync traffic on the local network. Do not expose port 873 directly to the internet. For migration between locations, connect the networks through a VPN and enable transfer encryption.

Create destination users, groups, and folders first

A pull-based rsync task copies data into the destination NAS account and permission environment. It does not migrate the source NAS user and group database.

Even when the same username exists on both devices, its underlying user or group ID may be different.

Before copying family or team data:

1. Create the required destination users and groups.
2. Create a separate destination shared folder for each permission boundary.
3. Assign preliminary access to those destination folders.
4. Migrate each person’s or team’s files into the correct folder.
5. Test access with the actual destination accounts before cutover.

Do not pull every user’s private folders into one shared destination and plan to separate them later. That can leave thousands of files requiring manual permission reassignment.

Create the rsync task on UGREEN NAS

On the destination UGREEN NAS:

1. Install and open Sync & Backup.
2. Select Backup & Restore.
3. Click Add.
4. Select Backup Rsync Server.
5. Enter the source NAS IP address.
6. Enter the rsync port. The default is 873.
7. Enter the migration account username and password.
8. Enable transmission encryption when required.
9. Confirm the connection.
10. Select the source folders.
11. Select an empty destination folder.
12. Review the filename, extension, and file-size filters.
13. Select Incremental Backup.
14. Enable Back up immediately after creation.
15. Name the task and start the transfer.

Review the default filters before continuing. Do not set a maximum file size unless you deliberately want to omit large files. An unintended limit can exclude videos, disk images, archives, or virtual-machine files without stopping the rest of the task.

UGOS Pro offers three relevant backup behaviors:

• Incremental Backup: Copies new and changed files while retaining destination files that were deleted from the source.
• Image Backup: Makes the destination match the source, including source deletions.
• Multi-version Backup: Creates retained versions according to the configured version policy.

Use Incremental Backup for migration. Image Backup can propagate an accidental source deletion before you notice it.

Migrate a large library in stages

A 20TB household or team library does not need to move as one job. Divide it into logical sections such as personal folders, family shares, work data, media, and backup repositories.

Apply the two-pass process to each section:

1. Create the destination folder and assign its users and groups.
2. Run the initial rsync transfer while the source folder remains available.
3. Review the log and resolve skipped, filtered, or failed files.
4. Stop changes to that source folder.
5. Pause synchronization, phone uploads, backups, and media indexing that write to it.
6. Stop any database, container, or virtual machine using that data.
7. Run the same incremental task again.
8. Verify the folder contents and destination permissions.
9. Switch its users or applications to the new NAS.
10. Make the source folder read-only.
11. Continue with the next section.

This keeps each cutover manageable and limits the effect of a permission or transfer mistake. It also allows a large household migration to run over several nights without taking every folder offline at once.

For databases and container application data, stopping the application before the final pass is mandatory. A copy made while the database is writing is only crash-consistent and may not provide a usable recovery state.

Treat Time Machine and backup repositories separately

Some folders contain structures that an ordinary file-copy workflow may not preserve correctly.

Time Machine sparsebundles, virtual-machine disk images, and backup repositories can depend on:

• Hard-link relationships
• Sparse allocation
• ACLs
• Extended attributes
• Application-specific indexes or databases

The standard UGOS Pro rsync interface does not document controls for preserving all of these structures. A hard-linked repository copied without retaining those relationships can consume much more space. A sparse file copied as fully allocated data can also become much larger at the destination.

For Time Machine, the safer migration is:

1. Stop Time Machine on every Mac using the old destination.
2. Keep the existing backup history on the old NAS.
3. Create a new Time Machine destination and quota on the new UGREEN NAS.
4. Start a fresh backup.
5. Retain the old history until it is no longer needed.

If preserving an existing sparsebundle is essential, copy the complete bundle while no Mac is writing to it. Then mount and verify it from macOS before removing the source. Do not assume that a completed file-copy task proves that the Time Machine history remains usable.

Use an application-supported export or replication method for virtual machines and backup repositories whenever one is available.

Troubleshoot rsync migration failures

If the network and storage path appear healthy but transfers remain slow, follow our NAS performance troubleshooting workflow.

How to Move a UGREEN Storage Pool to Another UGREEN NAS

Physical drive migration avoids copying every file, but it applies only to a storage pool created by UGOS Pro.

It cannot convert Synology, QNAP, TrueNAS, Unraid, SHR, ZFS, or RAID-Z arrays into UGREEN internal storage.

Before moving the drives:

• Confirm that the source and destination devices run UGOS Pro.
• Update both devices before the migration.
• Confirm that the destination has enough bays for every pool member.
• Confirm that the storage pool and every drive report a normal state.
• Move every member of the RAID array together.
• Label each drive with its current bay number.
• Check the exact drives against the UGREEN NAS compatibility list.
• Remove SSD cache safely before moving any cache device.
• Back up the UGOS Pro configuration.
• Connect the destination NAS to stable power, preferably through a UPS.

A four-drive RAID 5 pool requires the complete member set. Installing only three members does not turn it into a new three-drive RAID 5 pool.

Move the drives and convert the pool

1. Create and verify an independent backup.
2. Back up the old NAS configuration.
3. Confirm that the source storage pool is healthy.
4. Shut down the old NAS completely.
5. Disconnect its power cable.
6. Remove and label each drive.
7. Install the complete drive set in the same order in the new NAS.
8. Start the new NAS and sign in to UGOS Pro.
9. Open Storage > Hard Drive.
10. Select the HDD/SSD tab.
11. Find the migrated drives in the unused-drive list.
12. Open the … menu and select Use.
13. Select Internal Storage.
14. Review the detected pool and complete the confirmation.
15. Enter the administrator password when prompted.
16. Wait for UGOS Pro to convert the existing pool.
17. Confirm that its shared-folder data is accessible before restoring other services.

Do not select initialization, data erasure, or new-pool creation for the migrated drives. Those operations can destroy the storage structure you are trying to preserve.

The conversion retains the storage pool and its files. Application data installed on that pool under the previous system is deleted during conversion. Reinstall applications and restore their configuration, databases, Docker data, and virtual machines separately.

Physical migration takes the source NAS offline as soon as its drives are removed. Unlike rsync, it leaves no working source system available for immediate fallback.

What Does Not Migrate with the Files?

After restoring a UGREEN configuration backup, test the accounts and permissions before giving users access. A successful configuration import does not prove that every path, application, or storage reference still points to the intended location.

Verify the Migration Before Retiring the Source

A destination folder existing does not prove that the migration succeeded. Verification needs to confirm the data, permissions, applications, and recovery path.

1. Confirm that every migration task or storage-pool conversion reports completion.
2. Review the logs for skipped, filtered, or failed files.
3. Compare file counts and logical folder sizes between source and destination.
4. Investigate unexpected size differences, especially in hard-linked or sparse data.
5. Open representative photos, videos, documents, archives, and project files.
6. Generate and compare SHA-256 hashes for irreplaceable archives or a representative sample.
7. Test each user account against folders it should and should not access.
8. Open application databases, media libraries, virtual machines, or repositories through the applications that use them.
9. Update mapped drives, backup software, media servers, and other clients to use the new NAS.
10. Run the first independent backup from the destination NAS.
11. Restore several files from that backup to a temporary folder.
12. Keep the source NAS unchanged or read-only until the restore test succeeds.

Only then should you delete migration tasks, erase source drives, reuse the old enclosure, or transfer the old device to someone else.

The migration is complete when the new UGREEN NAS serves the files, enforces the intended permissions, runs the required applications, and restores data from an independent backup. A completed copy is only the first checkpoint.