Synology NAS Data Recovery Service

Common Synology Error Codes

DSM reports failures through specific error states in Storage Manager. Each one tells you something different about what failed and what is still intact.

• Volume Crashed: The filesystem or RAID array is in a state DSM cannot repair. This often means multiple drives failed, or the Btrfs/EXT4 metadata is corrupt. Do not click Repair in Storage Manager. Our Synology volume crashed recovery guide covers the underlying architecture and safe diagnostic steps.
• Storage Pool Degraded: One member drive has dropped out, but the pool is still running on reduced redundancy. If a second drive fails before a rebuild completes, the pool crashes. Power down and contact us rather than starting a rebuild on aging drives.
• Drive Status: Critical/Failed: DSM has marked a specific drive as unusable. SMART data may show reallocated sectors, pending sectors, or read errors. This drive likely needs professional imaging with retry control before it is usable in a reconstruction.
• Beep codes (long continuous beep): A long continuous beep on models like the DS920+ or DS1621+ signals a critical system warning, typically a volume crash or thermal shutdown. Do not swap drives in or out while the unit is beeping.

All of these errors share a common first step: power the NAS down, label each drive with its bay number, and avoid any further writes. The more you interact with a failing array, the more metadata gets overwritten.

Btrfs and EXT4 Filesystem Recovery in Synology Environments

Synology uses Btrfs by default on newer models (DS920+, DS1621+, DS423+) and EXT4 on older hardware. The recovery approach differs for each filesystem.

Both filesystems sit on top of the SHR/mdadm layer, which itself must be reconstructed first. We image every member, capture the mdadm superblocks and LVM metadata, rebuild the virtual array, and only then address the filesystem. XFS volumes (less common on Synology, but supported) follow a similar approach with XFS-specific log replay.

Why You Shouldn't Swap Drives After a Synology Beep Code

Swapping drives, reinitializing, or reinstalling DSM after a failure overwrites the exact metadata we need to reconstruct your array. Every write to a member drive reduces the chance of a full recovery.

1. Inserting a new drive triggers a rebuild. DSM will attempt to rebuild the RAID array onto the new member. If the remaining drives have weak sectors or unreadable regions, the rebuild stalls or writes bad parity, corrupting the array further.
2. Reinstalling DSM overwrites system partitions on every drive. Synology stores DSM system files and swap on the first two partitions (md0, md1) of each member. A standard reinstall rewrites these system partitions and their RAID superblocks. User data resides on Partition 3+ (md2+), which a Mode 2 reinstall does not directly touch. However, partition table changes or selecting "Erase all data" can make array reconstruction harder.
3. Swapping drive order confuses the mdadm layer. SHR records which physical drive occupies which role in the array. Moving drives between bays without preserving the original order can cause DSM to misidentify members or trigger an unwanted reinitialization.
4. Factory reset destroys LVM and filesystem metadata. A full reset through DSM's Control Panel erases the LVM volume group that ties multiple mdadm arrays together in SHR configurations. This metadata is small but irreplaceable.

The safe response to a Synology beep code: power off, label drives by bay position, and ship them to us. We will image each drive in its current state before any analysis begins.

How We Recover Data from a Failed Synology NAS

We follow an image-first, offline reconstruction workflow. Your original drives are never modified. All assembly and filesystem work happens on cloned images.

1. Free evaluation: We document your Synology model (DS920+, DS1621+, RS1221+, etc.), the DSM error state, RAID/SHR configuration, filesystem type (Btrfs or EXT4), and any prior recovery attempts.
2. Write-blocked imaging: Each member drive is connected through a hardware write-blocker and imaged with PC-3000 or DeepSpar. Drives with weak heads or bad sectors get conservative retry profiles and head maps to maximize data capture without accelerating degradation.
3. Mechanical repair (if needed): Drives that click, beep, or refuse to spin require clean-bench head swaps with matched donor parts before imaging can proceed.
4. RAID/SHR reconstruction: We read mdadm superblocks from the imaged copies, determine stripe size, parity rotation, and member order. For SHR with mixed-size drives, we also reconstruct the LVM layer. PC-3000 RAID Edition performs virtual assembly from images, never from originals.
5. Filesystem extraction: Once the virtual array is assembled, we mount and extract the Btrfs or EXT4 filesystem. For Btrfs, we traverse subvolume trees and recover snapshots where applicable. For EXT4, we perform journal replay and inode table reconstruction.
6. Verification and delivery: Recovered data is copied to a target drive, verified against your priority file list, and shipped back. Working copies are securely purged on request.

How Much Does Synology NAS Recovery Cost?

Synology recovery uses two-tiered pricing: a per-member imaging fee based on each drive's condition, plus a $400 to $800 array reconstruction fee. If we recover nothing, you owe $0.

A typical four-bay Synology (DS920+) with one mechanically failed drive and three healthy members would cost the head swap fee for the failed drive, the logical imaging fee for each healthy drive, and the array reconstruction fee. Compare that to the opaque $10,000+ quotes from competitors who bundle everything into a single undisclosed number. We itemize every line so you know what you are paying for.

Synology Recovery FAQ