Disk Latency Observed on Database VM After VCF Upgrade from 4.5 to 5.2 Due to Outdated vSAN Disk Format

Products

• VMware vSAN

Issue/Introduction

Symptoms

After upgrading the environment from VMware Cloud Foundation (VCF) 4.5 to 5.2, disk latency was observed on a database virtual machine (VM) hosted on a vSAN OSA cluster.

• Observation Timeframe: Latency observed on few hard disks of Virtual Machine "TEST"

• Skyline Health Observation: Warning reported: Disk format version

Environment

VMware vSAN 8.x

VMware vSAN 7.x

Cause

The vSAN disk groups continue to use on-disk format version v15, which is the format introduced in vSAN 7.0 U3. After the VCF upgrade, the disk format was not upgraded to the version compatible with vSAN 8.0 U3.

This mismatch can lead to compatibility overheads and performance degradation, including increased latency.

Resolution

To resolve the latency issue and ensure optimal performance:

• Upgrade the vSAN disk format to the latest version supported by vSAN 8.0 U3.

This action ensures alignment with the current vSAN version and enables access to performance enhancements and stability improvements.

 

Additional Information

About the vSAN Disk Format to get details of Disk format version.

vSAN upgrade requirements for more information related to the upgrade requirements.