VM Power-On Failures on vSAN ESA Cluster

Products

• VMware vSAN

Issue/Introduction

Virtual machines running on a vSAN cluster fail to power on with the error "Failed to create swap file." The cluster experiences elevated latency, performance degradation, and slow resync operations. ESXTOP show significant controller latency spikes on hosts within the cluster.

Running esxtop from ESXi in SSH shows controller with high DAVG. See Using esxtop to identify storage performance issues for ESXi

Environment

vSAN ESA 8.x

Cause

The issue is caused by inconsistent storage controller firmware versions across the ESXi hosts within the vSAN cluster. This discrepancy results in controller-level latency spikes, which interfere with vSAN object operations and prevent the successful creation of VM swap files.

Resolution

1. Identify the current storage controller firmware version on all ESXi hosts in the cluster using the vSphere Client or command-line tools.
2. Compare the firmware versions across all hosts to detect any version drift.
3. Use vSphere Lifecycle Manager (vLCM) or hardware-specific management tools to standardize the storage controller firmware version across all affected ESXi hosts.
4. Reboot the updated ESXi hosts to ensure the new firmware version is active.
5. Monitor the vSAN controller latency and verify that the affected virtual machines power on successfully.

Additional Information

The "Power On virtual machine" failure symptom is also commonly associated with the following documented issue:

Error "Failed to create swap file" seen when attempting to power on a VM on a specific ESXi host within the cluster