Unable to attach empty optical drive to VM.

[adrianvanderwal]

While attempting to attach an ISO to a VM, I have accidently attached the physical optical drive to the VM:

Once this was selected an exclaimation alert appeared, indicating that I could not access the disk until the vm was stopped and started.

There were no ISO's in the ISO Repository at this stage, however, I added one at this point, and I could not change the selection to an ISO from the list.

I attempted a reboot from within the vm, it started ok, and the alert persisted. On stop/start, the vm failed to start.

[23:24 xcp-ng-1 ~]# xe vm-start uuid="3eb63bb4-29d1-f3a7-44a1-37fdb3711454"
Error code: SR_BACKEND_FAILURE_456
Error parameters: , Unable to attach empty optical drive to VM.,

1. How do I remove the optical disk so I can boot my vm?
2. Why couldn't I change the selected ISO?

Priority is low, as this is not a critical vm.

Edit:
Environment information
XCP-ng Version: v8.3.0

[adrianvanderwal]

I've managed to at least solve part of my issue.

Using this article, I managed to pull together the information I needed in order to remove the Optical Drive from the VM.

It refereced xe vbd-list. I found the manpage for that command, and noted that I could get the information I needed to remove the drive.

For future me to reference - because I know I'll somehow do this again in the future.

1. List all Virtual Block Devices (vbd's) associated to the vm (you can do this by vm-uuid, or vm-label)

[20:42 xcp-ng-1 ~]# xe vbd-list vm-uuid="3eb63bb4-29d1-f3a7-44a1-37fdb3711454" params="all"

Output should show the following.

uuid ( RO)                        : 7443c2f0-7c04-ab88-ccfd-29f0831c1aa0
                     vm-uuid ( RO): 3eb63bb4-29d1-f3a7-44a1-37fdb3711454
               vm-name-label ( RO): veeam01
                    vdi-uuid ( RO): 7821ef6d-4778-4478-8cf4-e950577eaf4f
              vdi-name-label ( RO): SCSI 2:0:0:0
          allowed-operations (SRO): attach; eject
          current-operations (SRO):
                       empty ( RO): false
                      device ( RO):
                  userdevice ( RW): 3
                    bootable ( RW): false
                        mode ( RW): RO
                        type ( RW): CD
                 unpluggable ( RW): false
          currently-attached ( RO): false
                  attachable ( RO): <expensive field>
                storage-lock ( RO): false
                 status-code ( RO): 0
               status-detail ( RO):
          qos_algorithm_type ( RW):
        qos_algorithm_params (MRW):
    qos_supported_algorithms (SRO):
                other-config (MRW):
                 io_read_kbs ( RO): <expensive field>
                io_write_kbs ( RO): <expensive field>


uuid ( RO)                        : 4d0f16c4-9cf5-5df5-083b-ec1222f97abc
                     vm-uuid ( RO): 3eb63bb4-29d1-f3a7-44a1-37fdb3711454
               vm-name-label ( RO): veeam01
                    vdi-uuid ( RO): 3f89c727-f471-4ec3-8a7c-f7b7fc478148
              vdi-name-label ( RO): [ESXI]veeam01-flat.vmdk
          allowed-operations (SRO): attach
          current-operations (SRO):
                       empty ( RO): false
                      device ( RO): xvda
                  userdevice ( RW): 0
                    bootable ( RW): false
                        mode ( RW): RW
                        type ( RW): Disk
                 unpluggable ( RW): false
          currently-attached ( RO): false
                  attachable ( RO): <expensive field>
                storage-lock ( RO): false
                 status-code ( RO): 0
               status-detail ( RO):
          qos_algorithm_type ( RW):
        qos_algorithm_params (MRW):
    qos_supported_algorithms (SRO):
                other-config (MRW): owner:
                 io_read_kbs ( RO): <expensive field>
                io_write_kbs ( RO): <expensive field>

2. Look for the device with type ( RW): CD. Take that uuid. In this case, the uuid was 7443c2f0-7c04-ab88-ccfd-29f0831c1aa0.
3. Destroy the vbd:

xe vbd-destroy uuid="7443c2f0-7c04-ab88-ccfd-29f0831c1aa0"

Once this was done, the vm started without issue.