How to Recover Data From a UGREEN NAS

Stop new writes before choosing a recovery method. Deleting a file usually marks its storage blocks as available rather than immediately erasing every block. New uploads, app activity, indexing, synchronization, and other writes can reuse that space and overwrite data that recovery tools might otherwise find.

If the NAS and storage pool are healthy, check Recycle Bin and snapshots first. If a drive is clicking, multiple RAID members are missing, or a rebuild has failed, stop repair attempts and preserve the original drives.

Before You Recover Anything, Identify the Failure

Start with the symptom you can confirm instead.

Do not initialize a disk, create a new storage pool, format a drive, or change RAID membership until you understand the failure. These actions can overwrite the file-system or RAID metadata required for recovery.

A factory reset is also not a file-recovery method. Resetting a UGREEN NAS does not delete personal files stored on its data drives, but it removes system settings, installed applications, Docker and virtual machine configurations, and synchronization or backup task records. Do not reset the NAS simply because a file has disappeared.

If the missing files are inside Safes

Do not reset Safes. If you still know the access password, you can generate a replacement .key file from the Safes settings by changing or re-entering the password.

If both the password and .key file are lost, the encrypted contents cannot be recovered, including by a recovery laboratory. Resetting Safes permanently deletes the data inside it.

Keep the password and key in separate secure locations. Files stored inside Safes are also excluded from UGOS Pro Sync & Backup, so irreplaceable files need a separate encrypted backup. See the UGREEN NAS encryption and security guide for the complete Safes limitations.

If the storage pool is healthy and the loss involves ordinary files, begin with the built-in recovery layers.

Recover Deleted Files From the UGREEN NAS Recycle Bin

UGOS Pro can retain files deleted from Personal Folders, shared folders, and other supported locations when Recycle Bin was enabled before the deletion.

To recover a deleted file:

1. Open Files in UGOS Pro.
2. Select Recycle Bin at the bottom of the sidebar.
3. Open the category that matches the original location:
   • Personal contains files deleted from your Personal Folder.
   • Shared contains deleted files from shared folders you have permission to access.
   • Users allows an administrator to view deleted files from other users’ Personal Folders.
4. Find the file or folder you need.
5. Select Restore to return it to its original location.

You can also select Download to save a copy to your computer without changing the NAS folder. This is safer when a file with the same name already exists or when you want to inspect the recovered copy before returning it to the working folder.

Recycle Bin cannot recover every deletion. The feature must have been enabled for the affected folder, and cleanup schedules can permanently remove older items. Selecting Delete, Empty, or disabling Recycle Bin for a folder can also permanently remove its retained files.

If the missing file is not in Recycle Bin, look for a snapshot created before the deletion or unwanted change.

Recover an Older File or Folder From a Snapshot

UGOS Pro snapshots are available only for folders stored on a Btrfs storage space. EXT4 storage spaces do not support snapshots.

The filesystem cannot be changed directly after the storage space is created. Switching between EXT4 and Btrfs requires reformatting, so snapshot-based recovery must be considered when the storage space is first configured.

A snapshot must also exist from before the file was deleted, overwritten, or corrupted. If no earlier snapshot exists, installing the Snapshot app after the loss will not recover the missing data.

Clone a shared-folder snapshot when you need selected files

Snapshot Clone creates a separate copy of a shared folder from an earlier point in time. The live folder stays in place, allowing you to inspect the cloned copy and recover only what you need.

1. Open Snapshot in UGOS Pro.
2. Select the affected shared folder.
3. Open its snapshot list.
4. Choose a snapshot created before the file was lost or changed.
5. Select Clone.
6. Open the cloned folder and inspect its contents.
7. Copy the required files back to the working folder.

The clone appears in the same storage space with a name based on the original shared folder. Cloning is supported for shared folders. Personal Folders cannot be cloned.

Because cloning does not replace the current folder, it is the safer starting point when only a few files need recovery.

Restore a snapshot when the whole folder must roll back

Snapshot Restore returns the folder’s data, permissions, and supported quota settings to the selected point in time.

Before starting:

• Stop uploads, downloads, file moves, copies, and extraction tasks in the folder.
• Ask other users to close files stored there.
• Preserve any current files that must not be replaced.

Open the folder’s snapshot list, select the required recovery point, and choose Restore. UGOS Pro creates a snapshot of the current folder state before restoration, but Restore should still be treated as a whole-folder rollback.

Snapshots remain on the same storage pool as the live data. They can recover earlier file states, but they cannot provide an independent copy after the entire pool fails. If neither Recycle Bin nor snapshots contain the missing data, check your external or cloud backup before moving to recovery software.

Stop Sync or Ransomware Before Restoring Data

Recovery will fail if the process that caused the loss is still running. An active sync task can delete the recovered file again, while an infected computer can encrypt a clean restored copy.

A cloud sync task deleted the NAS copy

In two-way synchronization and cloud-to-NAS synchronization, a deletion made in the cloud can propagate to the NAS. If Recycle Bin was enabled for the NAS destination folder, the deleted NAS copy should be retained there.

Use this order:

1. Pause the affected synchronization task.
2. Check the NAS Recycle Bin.
3. Check the cloud provider’s trash and version history.
4. Restore the file into a temporary location.
5. Decide which copy should become the authoritative version.
6. Resume synchronization only after confirming that the deletion will not propagate again.

Do not restore directly into the synchronized folder while the task is active.

Files were changed by ransomware

Unexpected extensions, ransom notes, mass renaming, or a sudden wave of file modifications require a different response:

1. Disconnect the affected computer from the network.
2. Pause NAS synchronization and scheduled backup tasks.
3. Prevent other clients from writing to the affected folders.
4. Identify the earliest suspicious file change.
5. Find the last snapshot or backup created before that time.
6. Remove the infection before restoring clean data.

A recent recovery point is not necessarily clean. Inspect it before returning its files to production. Follow the complete UGREEN NAS ransomware-response procedure if the incident extends beyond a few accidentally changed files.

Once propagation has been stopped, determine whether the storage hardware remains healthy.

Recover Data After a Drive or RAID Failure

A redundant RAID pool can remain readable after a supported number of drive failures, giving you time to secure important files and repair the pool.

Basic, JBOD, and RAID 0 do not provide drive-failure redundancy. A failed member in one of these configurations cannot be handled like a degraded RAID 1, RAID 5, RAID 6, or RAID 10 pool.

One drive failed, but the pool remains readable

If the storage pool is degraded and no verified backup exists:

1. Stop nonessential applications and write-heavy tasks.
2. Copy the most irreplaceable files to separate storage.
3. Record which drive and bay UGOS Pro identifies as abnormal.
4. Check the replacement drive against the UGREEN NAS compatibility list.
5. Replace only the failed member.
6. Start the supported storage-pool repair process.

Do not remove a second drive to test it elsewhere. The remaining members are keeping the pool accessible, and another mistake can convert a repairable degraded array into a recovery case.

Follow the complete failing NAS drive replacement procedure before opening the enclosure.

Multiple drives are missing or the rebuild has failed

Stop normal repair attempts when:

• More drives are missing than the RAID mode can tolerate.
• Several drives report abnormal health at the same time.
• The original pool appears as uninitialized.
• UGOS Pro cannot identify enough RAID members.
• A rebuild repeatedly fails.
• The pool becomes inaccessible during repair.

Record the NAS model, RAID mode, drive serial numbers, and original bay positions. Label each drive before removing it.

Do not:

• Create a new pool on the original drives.
• Accept an initialization prompt.
• Reorder the drives.
• Replace multiple members at once.
• Run CHKDSK against individual drives.
• Repeat rebuilds without diagnosing the failure.
• Save recovered data back to the affected array.

Use the RAID rebuild failure guide to distinguish a correctable rebuild problem from a case requiring deeper recovery.

A drive clicks or has physical damage

Power off the NAS if a drive clicks, scrapes, repeatedly spins up and down, smells burnt, or has suffered an impact, liquid exposure, or electrical event.

Recovery software cannot repair damaged heads, platters, motors, or electronics. Each additional power cycle can make physical damage worse. Seagate’s data-loss guidance likewise advises against powering up a physically damaged drive or writing changes to it.

Do not open a hard drive outside a professional cleanroom. Keep all array members together because RAID reconstruction can require data and metadata from the complete drive set.

The NAS enclosure failed but the drives appear healthy

UGOS Pro supports moving a complete drive set to another compatible UGREEN NAS under supported conditions. The destination NAS needs enough bays, all RAID members must be moved, and their original order must be preserved. The system versions should also be the same or no more than one major release apart.

An unexpected enclosure failure creates more uncertainty than a planned migration. Record the drive order and contact UGREEN Support before inserting the disks into another NAS when the data is irreplaceable.

Should you contact UGREEN Support or a recovery laboratory?

UGREEN Support is the correct first contact when the drives appear healthy and the problem involves:

• UGOS Pro errors
• Storage-pool status
• System and error logs
• A supported drive-replacement procedure
• Migration to another compatible UGREEN NAS
• A possible enclosure or other UGREEN hardware failure

Support can help diagnose the product state and determine which supported action is safe. It cannot replace the block-level imaging, physical media repair, cleanroom work, or RAID reconstruction performed by a specialist recovery laboratory.

Use a recovery laboratory when drives have physical damage, multiple members have failed, the original drive order is unknown, a rebuild has altered the array, or the storage pool cannot be assembled safely.

Professional NAS or RAID recovery often costs four figures. Physical damage, more member drives, higher capacities, and emergency turnaround can push the quote into several thousand dollars. Most laboratories inspect the drives before giving a firm price, so compare the recovery cost with the value and replaceability of the lost data before authorizing work. Published recovery pricing also shows why a single-drive quote should not be treated as the price of multidrive RAID reconstruction. Ontrack

Can NAS Data-Recovery Software Help?

Data-recovery software can help in some logical-loss cases when the drives remain healthy and the software supports the file system, partition layout, and RAID configuration. It is not a universal method for recovering an inaccessible NAS.

A shared folder connected through SMB exposes files, not the raw storage blocks required for deep recovery. Specialized RAID recovery normally requires direct access to the member drives or sector-by-sector images of them.

Before using a recovery application, confirm that:

• Every required RAID member is available.
• The software supports the NAS file system and RAID layout.
• The drives show no signs of physical failure.
• The application can scan the array or disk images without writing to them.
• Recovered files will be saved to separate storage.

Do not enable SSH as a general recovery prerequisite. Remote administrative access does not make unsupported recovery software compatible with a UGOS Pro storage pool.

For important data, create complete sector-by-sector images and work from those images instead of repeatedly scanning the original drives. Stop if an original drive begins reporting read errors, disconnecting, or producing abnormal sounds during imaging.

No recovery method guarantees that every file will be usable. Partial overwriting, physical media damage, missing RAID members, and unavailable encryption keys can make some data unrecoverable.

After Recovery, Make the Next Incident Easier

Once the recovered files have been opened and verified:

1. Enable Recycle Bin for Personal Folders and shared folders where accidental deletion is possible.
2. Use Btrfs for storage spaces that require snapshot recovery, then configure snapshot schedules and retention.
3. Maintain an independent backup outside the NAS storage pool. For off-site protection, use a versioned cloud destination through the UGREEN NAS cloud-backup workflow.
4. Keep Safes passwords and .key files in separate secure locations.
5. Test each recovery layer by restoring a sample file from Recycle Bin, a snapshot, and the independent backup.

A backup has not completed its job until you have successfully restored and opened a file from it.