Synology Hybrid RAID (SHR) is an automated RAID management system that allows users to create storage volumes with mismatched drive capacities. It’s flexible by design — and that flexibility has made it a popular choice for NAS users.
The tradeoff: SHR is complex, and when data loss occurs, data recovery engineers must understand the complexity of multi-layered storage architecture in order to see results.
Below, we’ll discuss the basics of SHR and its impact on data recovery. If you’ve lost data from an SHR RAID — or any other storage device — we’re here to help. Set up a free evaluation online or call 1-800-237-4200 to speak with an expert.
How SHR Complicates Data Recovery
When a Synology NAS experiences a mechanical drive failure, firmware corruption, or a crashed volume status, the recovery process is significantly more intensive than a traditional RAID rebuild.
That doesn’t necessarily mean a worse prognosis; the vast majority of Synology cases are fully recoverable, provided that the data is not overwritten. We strongly recommend turning the device off, regardless of whether it has sustained physical media damage. Do not attempt to rebuild a failed RAID without guidance unless you’re willing to lose the data.
Challenges of SHR data recovery include:
- Nested mdadm and LVM Layers: SHR is effectively a series of mdadm devices aggregated by LVM. That creates disparate parity sets, which must be precisely aligned before the LVM Physical Volumes (PVs) can be mapped.
- LVM Metadata: Because the Volume Group (VG) and Logical Volumes (LVs) span multiple sub-RAID sets, any corruption in the LVM metadata area can lead to a PV not found error. Even if the individual RAID slices are reconstructed, the file system isn’t visible until the LVM headers are manually repaired.
- Proprietary Striping Quirks: While based on the Linux mdadm utility, Synology’s DiskStation Manager (DSM) handles metadata in a specific way that standard recovery software often misidentifies. Miscalculating the stripe size or offset of even one sub-array in the stack results in complete data corruption across the entire volume.
- Btrfs Copy-on-Write (CoW) Complexity: Most modern Synology units use Btrfs on top of the SHR/LVM stack. Engineers must have significant experience with the Btrfs format.
Professional SHR Recovery at Datarecovery.com
Recovering data from a failed SHR volume requires a laboratory environment capable of handling both physical hardware repair and complex logical reconstruction. Datarecovery.com provides specialized services tailored to the Synology ecosystem.
- Certified Cleanroom Data Recovery: If your Synology failure is caused by storage media failure, we perform all mechanical repairs in-house. We maintain an extensive inventory of donor components for all drives commonly found in Synology units.
- Advanced File System Parsing: We go beyond simple file recovery. Our labs can often reconstruct corrupted iSCSI LUNs and virtual machine images (VMDK/VHDX) by directly analyzing the Btrfs tree structures and mapping them back to the underlying RAID geometry.
- Remote Recovery Options: For logical failures or deleted data where the hardware is still functional, we offer remote data recovery services to minimize downtime for businesses.
Don’t risk your data with automated software or forced rebuilds that can permanently overwrite your parity. Our engineers have a proven track record of successful recovery from even the most complex SHR and Btrfs configurations.
Call us at 1-800-237-4200 or start a new case online to get a free laboratory evaluation and a firm price quote.
