Named Disks using a Shared Controller fail to connect to a particular bus:unit combination even though the slot is available

Products

• VMware Cloud Director

Issue/Introduction

Symptoms:

• Named Disks using a Shared Controller fail to connect to a particular bus:unit combination even though the slot is available
• (bus:unit) is not available error message is observed when connecting a Named Disk

Environment

VMware Cloud Director 10.x

Cause

This issue occurs only with powered on VMs.
When the Named Disk is first mounted a chosen bus:unit is decided upon.
This same bus:unit value is then used for all subsequent VMs, meaning if a VM does not have this slot free, the mounting will fail.

Note:
You will also see the above error if the slot is free for the VM, but the Controller is not shared.

Resolution

This is a Known Issue affecting Cloud Director 10.3.

Workaround:

1. Change the bus:unit number, on the existing attached VMs.
   1. Detach the disk from the VM.
   2. Attach the disk specifying the required bus:unit slot.
2. Recreate the Controller
   1. Remove all the disks on the bus which shared disk is currently using.
   2. Power-off the VM, if it is powered-on.
   3. Attach the shared disk again.