EMC CLARiiON, Celerra and VNXe Data Recovery
CLARiiON, Celerra and VNXe represent EMC's mid-range block and unified storage lineage before and alongside the VNX consolidation, and remain in service in many long-lived environments. Each family uses its own operating environment and management layer — FLARE on CLARiiON, DART on Celerra Data Movers, and a simplified Unisphere stack on VNXe — so a recovery evaluation needs to identify which lineage a given array belongs to before any assumptions are made about its internal layout.
Platform Lineage and Naming
CLARiiON began as EMC's mid-range block array line, progressing through the CX, CX3 and CX4 series plus the entry-level AX series, all running the FLARE operating environment and managed through Navisphere and later Unisphere. Celerra was EMC's NAS gateway and unified platform, built around one or more Data Movers running the DART operating system layered in front of CLARiiON or Symmetrix back-end storage, in NS and NX model families.
CLARiiON and Celerra were subsequently converged into the VNX platform, unifying block and file management under a common Unisphere interface; that convergence and the VNX/VNX2 platform itself are covered on a separate VNX page and are not duplicated here. VNXe was introduced as a distinct, simplified unified array line for smaller deployments — the VNXe 3100, 3150, 3200 and 3300 — running its own more streamlined operating environment rather than full FLARE/DART, and is treated here as part of this earlier mid-range family rather than as part of VNX proper.
Because these platforms span roughly fifteen years of EMC's mid-range history, the same physical drives can appear behind very different metadata layers depending on which generation and operating environment was in use.
- CLARiiON CX, CX3, CX4, AX series — FLARE operating environment
- Celerra NS and NX series — DART operating environment, Data Movers
- Navisphere / Unisphere management
- VNXe 3100, 3150, 3200, 3300
- UxFS — Celerra/DART file system, nas_db configuration database
- Note: VNX and VNX2 convergence covered on the separate VNX page
Generations and Models We Evaluate
| Generation / family | Models |
|---|---|
| CLARiiON block | CX, CX3, CX4 (various model numbers), AX series |
| Celerra unified/NAS gateway | NS series, NX series, integrated and gateway configurations |
| VNXe | VNXe 3100, 3150, 3200, 3300 |
Architecture and Data Layout
CLARiiON organises physical drives into RAID groups under FLARE, with LUNs bound directly to a RAID group or, in later FLARE releases, carved from virtual provisioning pools. Navisphere and later Unisphere hold the configuration metadata describing this binding, and that metadata has to be reconstructed alongside the RAID stripe during a recovery.
Celerra layers one or more Data Movers running DART in front of block storage (typically CLARiiON, sometimes Symmetrix), presenting NFS and CIFS shares backed by the UxFS file system. Data Mover configuration is tracked in the nas_db database, and a Celerra recovery typically involves both the back-end block LUNs and the Data Mover's file system and configuration layer.
VNXe simplifies this stack into a single unified operating environment with its own storage pool and share/LUN abstraction, aimed at smaller deployments without the separate FLARE/DART split — but it still uses its own proprietary metadata rather than a generic file system directly on disk.
Protocols and formats: Fibre Channel, iSCSI, NFS, CIFS/SMB, FLARE, DART, UxFS, Navisphere/Unisphere
- CLARiiON RAID groups use standard RAID 1, 5 or 6 style striping at the physical layer, with LUN-to-RAID-group binding metadata maintained separately by FLARE.
- Celerra's UxFS file systems sit on top of CLARiiON or Symmetrix LUNs, so the block layer and the DART file system layer can each require separate reconstruction.
- VNXe storage pools abstract physical drives more directly than classic RAID groups, with the array's internal pool metadata determining how blocks map to presented LUNs and shares.
Failure Scenarios
Logical failures
- Corrupted or lost Navisphere/Unisphere or nas_db configuration database
- Deleted or reconfigured RAID groups, pools, LUNs or shares
- Celerra Data Mover failover or failback executed incorrectly
- UxFS file system corruption on Celerra or VNXe shares
- Failed FLARE or DART code upgrade
- Accidental reinitialisation of an array during decommissioning or redeployment
Hardware failures
- Multiple drive failures within a RAID group or pool beyond protection level
- Storage processor (SP) failure or failed SP failover on CLARiiON/VNXe
- Data Mover hardware failure on Celerra
- Cache card or battery/vault failure with unflushed writes
- Backend bus or enclosure 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 VNXe the same as VNX?
No. VNXe is a separate, simplified unified array line rather than the CLARiiON/Celerra-derived VNX/VNX2 platform. VNX itself is covered on its own dedicated page.
Our Celerra shares are missing after a Data Mover failover — is the data gone?
Not necessarily. Failover issues often leave the underlying UxFS file systems and back-end LUNs intact but inaccessible through the current configuration, which an evaluation can usually determine.
Do you need both the block array and the Celerra Data Mover?
Generally yes. Celerra's file systems live on Data-Mover-managed volumes that sit on top of the back-end block LUNs, so both layers are usually needed for a complete evaluation.