IBM SONAS Data Recovery
IBM SONAS (Scale Out Network Attached Storage) is a clustered NAS appliance that packages IBM's GPFS parallel file system into interface, storage and management nodes connected by an internal InfiniBand fabric. A recovery evaluation needs to treat SONAS as a GPFS cluster with an appliance layer wrapped around it, not a single NAS head.
Platform Lineage and Naming
IBM introduced SONAS as a purpose-built clustered NAS appliance, combining commodity server nodes with IBM's GPFS (General Parallel File System) underneath a unified global namespace. The appliance model bundled interface nodes for client access, storage nodes attached to disk enclosures, and management nodes for cluster administration, all interconnected over InfiniBand.
IBM later moved customers toward the Elastic Storage Server (ESS), which delivers the same GPFS-based approach in a denser, more integrated building-block form, and subsequently rebranded GPFS itself as IBM Storage Scale (formerly Spectrum Scale). SONAS deployments still in service should be treated as legacy clustered file systems requiring the same GPFS-aware recovery approach used for current Storage Scale systems.
- IBM Scale Out Network Attached Storage (SONAS)
- Built on GPFS — General Parallel File System, later Spectrum Scale, now IBM Storage Scale
- Successor platform: IBM Elastic Storage Server (ESS)
- Interface nodes, storage nodes, management nodes
Generations and Models We Evaluate
| Generation / family | Models |
|---|---|
| SONAS appliance | Interface nodes, storage nodes, management nodes, InfiniBand switches — packaged clustered NAS appliance |
| Storage enclosures | SAS-attached disk enclosures behind storage nodes |
| Successor | IBM Elastic Storage Server (ESS) — denser GPFS-based building block replacing SONAS |
Architecture and Data Layout
A SONAS cluster separates roles across node types: interface nodes present NFS and SMB shares to clients, storage nodes own the back-end disk enclosures, and management nodes coordinate cluster configuration and health. All nodes communicate over an internal InfiniBand fabric for low-latency cluster traffic.
Underneath the appliance layer, SONAS relies entirely on GPFS to stripe files and metadata across all storage nodes in the cluster, presenting a single global namespace regardless of which interface node a client connects through.
Because the file system internals are GPFS, the detailed recovery approach for stripe groups, metadata, NSDs and quorum — the layer that ultimately determines what can be reconstructed — is the same discipline used on current IBM Storage Scale/GPFS systems.
Protocols and formats: NFS, SMB/CIFS, GPFS (internal), InfiniBand cluster fabric, HTTP/FTP (SONAS gateway protocols)
- Data and metadata are striped across all storage nodes' disks by GPFS, so no single storage node holds a complete, self-contained copy of any given file system.
- Cluster quorum and configuration metadata are held by designated nodes; loss of quorum information alongside disk-level damage compounds what needs to be reconstructed.
Failure Scenarios
Logical failures
- Accidental deletion of shares, filesets or files across the global namespace
- GPFS file system corruption after a failed code upgrade or configuration change
- Loss of cluster configuration or quorum data
- Failed migration or share re-export leaving inconsistent metadata
- Snapshot mismanagement at the fileset or file system level
Hardware failures
- Multiple storage node or enclosure failures beyond configured protection
- InfiniBand fabric failure isolating nodes from the cluster
- Interface node failures affecting client-facing access
- Multiple concurrent disk failures within a storage node's enclosure
- Management node failure combined with storage-side faults
What Not To Do Before an Evaluation
- Do not run rebuilds, reconstructions or re-initialisations against an array that has already lost more drives than its protection level allows.
- Do not recreate pools, aggregates, disk groups, storage pools or clusters — these operations write new metadata over the structures a recovery needs.
- Do not swap drives between slots, and do not reorder shelves. Record the original slot and shelf positions before removing anything.
- Do not run file-system repair tools against production volumes before the underlying storage layer has been evaluated.
- Do not restore a backup or replication set over the affected volumes until the recovery scope has been assessed.
- Do not eradicate deleted volumes or empty recycle/destroyed states on platforms that hold deleted data for a retention window.
Our Evaluation and Recovery Process
- Intake and platform identification — array model, generation, firmware, protection layout and the sequence of events that led to the failure.
- Read-only evaluation of the media and array structures, including assessment of drive health and the extent of any physical damage.
- Forensic imaging of all contributing media, with cleanroom work where drives require it. Originals are preserved unaltered.
- Reconstruction of the storage layer — pools, aggregates, parity groups, chunklets, extent groups or objects — from the images.
- Extraction of the layers above: file systems, virtual machines, databases, mailboxes and shares.
- Verification against a file list and customer-nominated critical data, followed by secure return on encrypted media.
Frequently Asked Questions
Is SONAS the same as GPFS?
SONAS is an appliance built around GPFS. The appliance adds interface, storage and management node roles and an InfiniBand fabric, but the underlying file system logic is the same GPFS technology used in IBM Storage Scale today.
Can a single storage node be recovered on its own?
Rarely in isolation. GPFS stripes data and metadata across all storage nodes in the cluster, so an evaluation typically needs to consider the full set of nodes involved in the affected file system.
Is SONAS still supported?
IBM has moved customers toward the Elastic Storage Server, and SONAS is best treated as a legacy platform — but the GPFS recovery discipline that applies to current Storage Scale systems still applies to SONAS clusters.