Chapter 7. Premigration checklists

Before you migrate your application workloads with the Migration Toolkit for Containers (MTC), review the following checklists.

7.1. Cluster health checklist

❏ The clusters meet the minimum hardware requirements for the specific platform and installation method, for example, on bare metal.
❏ The MTC version is the same on all clusters.
❏ All MTC prerequisites are met.
❏ All nodes have an active OpenShift Container Platform subscription.
❏ You have verified node health.
❏ The identity provider is working.
❏ The migration network has a minimum throughput of 10 Gbps.
❏ The clusters have sufficient resources for migration.
Note
Clusters require additional memory, CPUs, and storage in order to run a migration on top of normal workloads. Actual resource requirements depend on the number of Kubernetes resources being migrated in a single migration plan. You must test migrations in a non-production environment in order to estimate the resource requirements.
❏ The etcd disk performance of the clusters has been checked with fio.

❏ You have checked for persistent volumes (PVs) with abnormal configurations stuck in a Terminating state by running the following command:
```
$ oc get pv
```
❏ You have checked for pods whose status is other than Running or Completed by running the following command:
```
$ oc get pods --all-namespaces | egrep -v 'Running | Completed'
```
❏ You have checked for pods with a high restart count by running the following command:
```
$ oc get pods --all-namespaces --field-selector=status.phase=Running \
  -o json | jq '.items[]|select(any( .status.containerStatuses[]; \
  .restartCount > 3))|.metadata.name'
```
Even if the pods are in a Running state, a high restart count might indicate underlying problems.
❏ The cluster certificates are valid for the duration of the migration process.
❏ You have checked for pending certificate-signing requests by running the following command:
```
$ oc get csr -A | grep pending -i
```
❏ The registry uses a recommended storage type.
❏ You can read and write images to the registry.
❏ The etcd cluster is healthy.
❏ The average API server response time on the source cluster is less than 50 ms.

❏ The cluster has the correct network configuration and permissions to access external services, for example, databases, source code repositories, container image registries, and CI/CD tools.
❏ External applications and services that use services provided by the cluster have the correct network configuration and permissions to access the cluster.
❏ Internal container image dependencies are met.
❏ The target cluster and the replication repository have sufficient storage space.