Migration fails with HTTP or 500 error upon POST call to trigger mobility emergency fix

The migration fails with HTTP or 500 error upon a POST call to trigger the mobility emergency fix.

You might see some issues in the Virtual appliance update job log on the target IBM® Cloud Pak System Software instance. For example, the following snippet is related to triggering mobility fix on the virtual machine (the C:\vmmobilityfix folder is not uploaded to the virtual machine):

pooljvm.1644936339850.49332 [02-15-22 15:49:45] 0185 com.ibm.purescale.utils.RESTUtils | postImpl return from post on https://10.227.88.235/resources/virtualApplications/d-cc3d7ee8-2079-4fbb-990f-de471ad268c4/operations/ is {
  "errorMessage": "java.lang.RuntimeException: java.net.ConnectException: Connection timed out",
  "rootCause": "com.ibm.maestro.util.wrapper.exception.MaestroServerException: java.lang.RuntimeException: java.net.ConnectException: Connection timed out",
  "errorStatusCode": 500,
  "message": "java.lang.RuntimeException: java.net.ConnectException: Connection timed out"
}

To address this issue, you must run some recovery steps on Linux® or Windows virtual machines:

Attention: Engage IBM Support when you run the following steps if the issue is applicable to your Linux or Windows virtual machines.

On a Linux virtual machine

The Workload Mobility emergency fix can be retrieved from the IBM Cloud Pak System user interface of the source IBM Cloud Pak System Software instance (Pattern Development > Emergency Fixes > vm-mobilityfix). In cases where the emergency fix is no longer available from the IBM Cloud Pak System user interface, work with IBM Support to retrieve it from /tmp/fixpatch/zip on the target IBM Cloud Pak System Software instance.
Manually transfer the Workload Mobility emergency fix to the operating system on the Linux virtual machine of the virtual system instance.
Create a directory as /tmp/vm-mobilityfix and then extract the contents at /tmp/vm-mobilityfix.
Manually run the Workload Mobility emergency fix as root on the Linux virtual machine of the virtual system instance with the following command:
```
# /tmp/vm-mobilityfix/install.sh
```
Monitor the status of the virtual system instance on the target IBM Cloud Pak System Software instance. After a few minutes, the status changes from ERROR to RUNNING.

On a Windows virtual machine

The Workload Mobility emergency fix can be retrieved from the IBM Cloud Pak System user interface of the source IBM Cloud Pak System Software instance (Pattern Development > Emergency Fixes > vm-windowsmobilityfix). In cases where the emergency fix is no longer available from the IBM Cloud Pak System user interface, work with IBM Support to retrieve it from /tmp/fixpatch/zip on the target IBM Cloud Pak System Software instance.
Manually transfer the Workload Mobility emergency fix to the operating system of the Windows 2012 virtual machine of the virtual system instance.
Create new directory as C:\vm-windowsmobilityfix and then extract the contents at C:\ vm-windowsmobilityfix.
Manually run the Workload Mobility emergency fix as Administrator on the Windows 2012 virtual machine of the virtual system instance from the following location:
```
C:\vm-windowsmobilityfix\install.bat
```
Monitor the status of the virtual system instance on the target IBM Cloud Pak System Software instance. After a few minutes, the status changes from ERROR to RUNNING.

Note: The folder name that is specified for the Windows mobility fix is vm-mobilityfix in the earlier release of IBM Cloud Pak System, whereas it is vm-windowsmobilityfix in IBM Cloud Pak System Version 2.3.4