"Failed unmounting /storage/log" error is seen during vCenter Server virtual machine reboot on the virtual machine console window

Products

• VMware vCenter Server

Issue/Introduction

• During a graceful or forced reboot, the virtual machine console displays a failure message for the /storage/log partition.
  
  
• The following error appears in the remote console window for a few seconds when the vCenter Server virtual machine is rebooted:
  
  [FAILED] Failed unmounting /storage/log


• The vCenter Server eventually restarts completely without any manual intervention.

Environment

VMware vCenter Server 8.x

Cause

The operating system attempts to unmount all mounted storage devices during a shutdown or reboot and remounts them upon startup. However, some services take time to stop, which delays the unmount operation. Specifically, the rsyslogd service (flushing data to /storage/log/vmware/messages) often holds the file lock, preventing a clean unmount within the standard timeout window.

Resolution

This is expected behavior. This is not a functional issue and does not cause any impact on the vCenter Server operations. No manual intervention is required. Allow the vCenter Server appliance to continue its boot sequence.