Chapter 6. Troubleshooting
This section describes ways to troubleshoot migration issues and error messages.
6.1. Error messages
This section describes error messages and how to resolve them.
warm import retry limit reached
The warm import retry limit reached error message is displayed during a warm migration if the virtual machine (VM) has reached the maximum number (28) of changed block tracking (CBT) snapshots during the precopy stage. You must delete some of the CBT snapshots from the VM and restart the migration plan.
6.2. Using the must-gather tool
You can collect logs and information about MTV custom resources (CRs) by using the must-gather tool. You must attach a must-gather data file to all customer cases.
Prerequisites
-
You must be logged in to the OpenShift Virtualization cluster as a user with the
cluster-adminrole. -
You must have the OpenShift Container Platform CLI (
oc) installed.
Collecting logs and CR information
-
Navigate to the directory where you want to store the
must-gatherdata. Run the
oc adm must-gathercommand:$ oc adm must-gather --image=registry.redhat.io/migration-toolkit-virtualization/mtv-must-gather-rhel8:2.0.0
The data is saved as
/must-gather/must-gather.tar.gz. You can upload this file to a support case on the Red Hat Customer Portal.
6.3. Known issues
This section describes known issues and mitigations.
Network map displays a Destination network not found error
If the network map remains in a NotReady state and the NetworkMap CR manifest displays a Destination network not found error, the cause is a missing network attachment definition. You must create a network attachment definition for each additional destination network before you create the network map. (BZ#1971259)
Warm migration gets stuck during third precopy
Warm migration uses changed block tracking snapshots to copy data during the precopy stage. The snapshots are created at one-hour intervals by default. When a snapshot is created, its contents are copied to the destination cluster. However, when the third snapshot is created, the first snapshot is deleted and the block tracking is lost. (BZ#1969894)
You can do one of the following to mitigate this issue:
- Start the cutover stage no more than one hour after the precopy stage begins so that only one internal snapshot is created.
Increase the snapshot interval in the
vm-import-controller-configconfig map to720minutes:$ oc patch configmap/vm-import-controller-config \ -n openshift-cnv -p '{"data": \ {"warmImport.intervalMinutes": "720"}}'
