WeRecoverData

Hitachi NAS (HNAS) Data Recovery

HNAS is Hitachi's file services platform, built on BlueArc's FPGA-accelerated architecture and typically front-ending a VSP for large unstructured data estates. Recovery work here is file-system level: SiliconFS structures, storage pools and virtual servers, rather than raw RAID.

Platform Lineage and Naming

The platform originated with BlueArc, whose Si7500, Titan 2000/3000 and Mercury 50/100 file servers used FPGAs to accelerate file system operations. Hitachi Data Systems acquired BlueArc in 2011 and rebranded the line Hitachi NAS Platform.

Hitachi generations include HNAS 3080/3090, HNAS 4040/4060/4080/4100 and HNAS 5200/5300. HNAS also underpinned Hitachi Content Platform Anywhere and Hitachi Data Ingestor deployments in some estates.

Generations and Models We Evaluate

Architecture and Data Layout

HNAS nodes do not hold the data themselves: they present file services over LUNs (system drives) provided by a back-end Hitachi array. Those system drives are grouped into storage pools (spans), and SiliconFS file systems are created inside the pools and served by Enterprise Virtual Servers.

That split means a recovery normally involves two layers — the back-end array's parity groups and LDEVs, and the HNAS file system structures written into the resulting LUNs. Both must be reconstructed for files to be extracted with their names and directory structure.

Clusters of two or more nodes share the storage pools, so node failure alone rarely loses data; pool or file system damage is what puts files at risk.

Logical Failures

Hardware Failures

Encryption and Keys

Encryption on HNAS deployments is usually applied by the back-end array (controller-based encryption or self-encrypting drives). Those keys are required before the LUNs — and therefore the file systems on them — can be read.

Frequently Asked Questions

Our HNAS file system will not mount. Where does recovery start?

With the back-end LUNs. The file system lives inside system drives supplied by the array, so those LUNs (or the array drives behind them) are the recovery source.

Do you handle older BlueArc Titan systems?

Yes. Titan and Mercury systems use the same SiliconFS lineage and are treated as part of this family.

The nodes are dead but the array is fine. Is the data safe?

Usually the data is intact on the array. The task is reconstructing the SiliconFS structures inside those LUNs so files can be exported without working HNAS hardware.

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