Supportability of RAID 5 Erasure Coding on Hybrid Disk Groups for vSAN OSA Cluster.
Article ID: 424165
Updated On:
Products
Issue/Introduction
Symptoms:
Guidance is required regarding the feasibility of converting a Virtual Machine (VM) storage policy from RAID 1 (Mirroring) to RAID 5 (Erasure Coding) on a vSAN cluster with the following specifications:
Example :
- Cluster Size: 5 Nodes.
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Disk Configuration: Hybrid Disk Groups (SSD for Cache tier and HDDs for Capacity tier).
Environment
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Architecture: vSAN Original Storage Architecture (OSA).
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Version: VMware vSAN 8.X
Resolution
It is not possible to implement a RAID 5 vSAN storage policy in a vSAN OSA cluster using Hybrid Disk groups.
In the vSAN Original Storage Architecture (OSA), RAID 5 and RAID 6 (Erasure Coding) are technically restricted to All-Flash configurations. Although the cluster may meet the minimum host requirement (4 hosts for RAID 5), the presence of Magnetic Hard Disk Drives (HDDs) in the capacity tier makes the environment ineligible for erasure coding.
Additional Information
For detailed design considerations and official requirements, refer to the Broadcom TechDocs:
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