vCenter RDU failure: "An error occurred while mounting the ISO file. Verify if the device attached to the CDROM is a vCenter Server ISO file"

Products

• VMware vCenter Server 8.0

Issue/Introduction

When using the Reduced Downtime Upgrade feature in vCenter, a red banner error message is thrown: "An error occurred while mounting the ISO file. Verify if the device attached to the CDROM is a vCenter Server ISO file". This message is thrown on step 1, and prevents progression of the upgrade.

Environment

vCenter 8.0 Update 2 or newer

Cause

This error message can be thrown if there is no vCenter Server ISO mounted to the vCenter appliance VM's virtual disc drive that is of a newer version than what vCenter is running.

Ex:   If you are running vCenter Server 8.0 U3g, and mount the 8.0 U3g ISO to the vCenter disc drive, the error message will be thrown. This happens because the ISO cannot be used for upgrading/patching. That is, the vCenter is already running the version in the ISO.

Resolution

Validate the version of the vCenter Server patch/upgrade ISO attached to the disc drive. A version that is newer than the currently running version of vCenter Server is required.

Additional Information

For more information about vCenter Server's Reduced Downtime Upgrade feature (and steps for downloading and mounting the upgrade ISO), see "vCenter Server upgrades with the reduced downtime".