Computer name cannot be longer than 15 characters error occurs in VMware Cloud Director Availability

Products

• VMware Cloud Director

Issue/Introduction

Symptom1:

• When attempting to create a replication, convert a legacy placement replication to an RTVM, or performing a fail over or test fail over in VMware Cloud Director Availability (vCDA) 4.x, an error similar to the following is encountered:
  
  Unexpected VMware Cloud Director error. [...] Computer name cannot be longer than 15 characters

Symptom2: 

• When attempting to create a replication the VM may fail with the below error, if it has an underscore in it's computer name.

Unable to restore the Guest Customization settings of recovery virtual machine 'VM_NAME'.
Unexpected VMware Cloud Director error. [ UI-#######-####-####-####-############-####-##-###-########-####-####-####-##############] Computer name can only contain alphanumeric characters and hyphens. On non-Windows systems the name can also contain dots. It must not contain only digits.

Environment

VMware Cloud Director Availability 4.x

Cause

Due to restrictions in the guest OS for Windows based operating systems, computer names are restricted to 15 characters in VMware Cloud Director environments. In some cases, the computer name is set to the fully qualified domain name for the virtual machine rather than the host name for the device, which increases the length of the entry.

Also, if the VM host name contains an underscore, it is considered invalid.

 

Resolution

In order to avoid this restriction, confirm that the computer name is set to a value that is 15 characters or less in the source VMware Cloud Director site, as discussed in the following document:

Edit Virtual Machine Properties in the VMware Cloud Director Tenant Portal

If the computer name on the item includes the domain (e.g., mycomputer.mydomain.local), restrict the value to only include the host name (e.g., mycomputer).

If the computer name on the item includes an Underscore (e.g., VM_NAME), change the host name of the VM so that it does not contain any underscores.

For example:

If the host name is VM_PROD, rename it to VMPROD or another name without an underscore.

Additionally, validate that the guest customization configuration in VMware Cloud Director Availability (vCDA) is set to a value that is 15 characters or less and only contains the computer name:

1. Log into the vCDA provider portal interface with credentials that can manage the replication and navigate to the item.
2. Select the replication.
3. Click All Actions > Recovery settings.
4. Select Guest customization.
5. Expand the virtual machine settings for the item and review the General section.
6. If Guest customization is activated, confirm that the Computer Name contains a valid entry.

Additional Information

For more information, see: Configure recovery settings and guest customization

Also, see: Change the Guest OS Customization of a Virtual Machine