Recovering Data from a HP LeftHand vSAN: one of our latest successes

Degraded RAID 5, backup server down, HP LeftHand vSAN failure. Discover how Recoveo experts logically rebuilt the infrastructure and recovered nearly 100% of the data in under 2 days.

When Everything Fails at Once

Late last week, a local authority contacted us on emergency standby for a rare case: a severely degraded RAID 5, a non-functional backup server, and a critical virtual infrastructure at a standstill.
In just hours, their entire VM-based system became unavailable, risking major data loss and prolonged business interruption. Several virtualization specialists intervened… without success.

2 Production RAID 5s and 1 Backup RAID 5 Failed

First symptom: a RAID 5 with 4 out of 6 disks functional (the backup one), when at least 5 healthy disks are needed for standard reconstruction. It had suffered mechanical failures on two disks. Impossible to read them.
Then, a dual RAID 5 housed the production server… out of 12 disks, one was failed and another starting to degrade. With 11/12 disks, recovery was possible. But the issue wasn’t mechanical! It stemmed from data processing and interpretation problems.
Situation summary:

We rebuilt the RAID using standard recovery methods, but the main server remained unusable with our usual tools.
The backup server proved inoperable for conventional reconstruction.
In a production context, this scenario can halt operations for days—or longer—without data recovery solutions.

Complex Infrastructure: RAID 5, HP LeftHand vSAN, and VMFS

The client entrusted us with their infrastructure components:

A server with 2 RAID 5 arrays holding VMFS with VMDK files.
These VMDKs contained a rare, specific system: HP LeftHand (vSAN).

For reference, both RAID 5s had at least 1 faulty disk: one with mechanical failure, the other with multiple bad sectors.

Our mission: regain access to virtual volumes and hosted VMs, despite no usable backups and the storage structure appearing intact.
After analysis, our teams extracted 4 VMFS 6 volumes of about 1.2 TB each—nearly 4.8 TB of useful data, including around 20 virtual machines.

Custom Software Development to Reorganize Blocks

The uniqueness of this case: no standard software repair tools for data recovery or vSAN reconstruction worked. To access the data, we went beyond conventional tools.
Recoveo engineers developed proprietary software to:

Reconstitute the memory block distribution logic.
Reorganize vSAN-derived blocks.
Restore usable coherence to VMFS volumes for VMDK file recovery.
This advanced logical reconstruction approach was key to success in this extremely rare case, compensating for the server’s lack of logical interpretation and missing original client configuration.

Emergency Intervention: Friday Evening to Sunday Noon

Given the client impact, work proceeded on off-hours, evenings, and weekends:

Operations started: Friday at 9:07 PM.
Analysis, tool development, logical reconstruction, and data extraction.
Recovery report delivered: Sunday at 1:46 PM.
In under 2 non-business days, the company had:
List of recoverable data.
Essential VMs for resumption.
Media ready for their team’s reinstallation.
Success rate: 100%, especially on VMs the client reintegrated themselves.

Client Impact: Record-Time Business Resumption

Without this recovery:

Total loss of virtual machines.
Irrecoverable backup server.
Hard-to-estimate downtime costs, potentially long and expensive.
Thanks to the intervention:
Critical data recovered in under 2 days, delivered in under 4.
All VMs (client-confirmed) reinstalled upon receipt.
The authority resumed operations quickly after data reintegration.
This case highlights how advanced logical reconstruction makes the difference when no “classic” restoration works.

Key Takeaways from This Success Story

Extremely rare case combining degraded RAID 5, failed backup, and complex vSAN. The RAID was failing with 2/12 bad disks (1 fully failed).
Custom logical reconstruction to reorganize memory blocks and access VMFS volumes.
4.8 TB useful data recovered—around 20 virtual machines.
Intervention from Friday evening to Sunday noon, with 100% success rate.
At Recoveo, such cases confirm the importance of:
Consulting specialists quickly at first symptoms.
Relying on in-house R&D and software development for the most critical scenarios.

Facing degraded RAID 5, unreachable vSAN, or inaccessible VMs?
Contact our teams before any manipulation: a quick diagnosis can mean the difference between full recovery and permanent loss.