Chapter 2. Prerequisites

Review the following prerequisites to ensure that your environment is prepared for migration.

2.1. Software requirements

You must install compatible versions of OpenShift Container Platform and OpenShift Virtualization.

2.2. Storage support and default modes

MTV uses the following default volume and access modes for supported storage.

Note

If the OpenShift Virtualization storage does not support dynamic provisioning, MTV applies the default settings:

  • Filesystem volume mode

    Filesystem volume mode is slower than Block volume mode.

  • ReadWriteOnce access mode

    ReadWriteOnce access mode does not support live virtual machine migration.

Table 2.1. Default volume and access modes

ProvisionerVolume modeAccess mode

kubernetes.io/aws-ebs

Block

ReadWriteOnce

kubernetes.io/azure-disk

Block

ReadWriteOnce

kubernetes.io/azure-file

Filesystem

ReadWriteMany

kubernetes.io/cinder

Block

ReadWriteOnce

kubernetes.io/gce-pd

Block

ReadWriteOnce

kubernetes.io/hostpath-provisioner

Filesystem

ReadWriteOnce

manila.csi.openstack.org

Filesystem

ReadWriteMany

openshift-storage.cephfs.csi.ceph.com

Filesystem

ReadWriteMany

openshift-storage.rbd.csi.ceph.com

Block

ReadWriteOnce

kubernetes.io/rbd

Block

ReadWriteOnce

kubernetes.io/vsphere-volume

Block

ReadWriteOnce

2.3. Network prerequisites

The following prerequisites apply to all migrations:

  • IP addresses, VLANs, and other network configuration settings must not be changed before or after migration. The MAC addresses of the virtual machines are preserved during migration.
  • The network connections between the source environment, the OpenShift Virtualization cluster, and the replication repository must be reliable and uninterrupted.
  • If you are mapping more than one source and destination network, you must create a network attachment definition for each additional destination network.

2.3.1. Ports

The firewalls must enable traffic over the following ports:

Table 2.2. Network ports required for migrating from VMware vSphere

PortProtocolSourceDestinationPurpose

443

TCP

OpenShift nodes

VMware vCenter

VMware provider inventory

Disk transfer authentication

443

TCP

OpenShift nodes

VMware ESXi hosts

Disk transfer authentication

902

TCP

OpenShift nodes

VMware ESXi hosts

Disk transfer data copy

Table 2.3. Network ports required for migrating from Red Hat Virtualization

PortProtocolSourceDestinationPurpose

443

TCP

OpenShift nodes

RHV Engine

RHV provider inventory

Disk transfer authentication

443

TCP

OpenShift nodes

RHV hosts

Disk transfer authentication

54322

TCP

OpenShift nodes

RHV hosts

Disk transfer data copy

2.4. Source virtual machine prerequisites

The following prerequisites apply to all migrations:

  • ISO/CDROM disks must be unmounted.
  • Each NIC must contain one IPv4 and/or one IPv6 address.
  • The VM name must contain only lowercase letters (a-z), numbers (0-9), or hyphens (-), up to a maximum of 253 characters. The first and last characters must be alphanumeric. The name must not contain uppercase letters, spaces, periods (.), or special characters.
  • The VM name must not duplicate the name of a VM in the OpenShift Virtualization environment.
  • The VM operating system must be certified and supported for use as a guest operating system with OpenShift Virtualization and for conversion to KVM with virt-v2v.

2.5. Red Hat Virtualization prerequisites

The following prerequisites apply to Red Hat Virtualization migrations:

  • You must use a compatible version of Red Hat Virtualization.

  • You must have the CA certificate of the Manager.

    You can obtain the CA certificate by navigating to https://<engine_host>/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA in a browser.

2.6. VMware prerequisites

The following prerequisites apply to VMware migrations:

  • You must use a compatible version of VMware vSphere.
  • You must install VMware Tools on all source virtual machines (VMs).
  • If you are running a warm migration, you must enable changed block tracking (CBT) on the VMs and on the VM disks.
  • You must create a VMware Virtual Disk Development Kit (VDDK) image.
  • You must obtain the SHA-1 fingerprint of the vCenter host.
  • If you are migrating more than 10 VMs from an ESXi host in the same migration plan, you must increase the NFC service memory of the host.

2.6.1. Creating a VDDK image

The Migration Toolkit for Virtualization (MTV) uses the VMware Virtual Disk Development Kit (VDDK) SDK to transfer virtual disks from VMware vSphere.

You must download the VMware Virtual Disk Development Kit (VDDK), build a VDDK image, and push the VDDK image to your image registry. Later, you will add the VDDK image to the HyperConverged custom resource (CR).

Note

Storing the VDDK image in a public registry might violate the VMware license terms.

Prerequisites

Procedure

  1. Create and navigate to a temporary directory: 

    $ mkdir /tmp/<dir_name> && cd /tmp/<dir_name>
  2. In a browser, navigate to the VMware VDDK download page.
  3. Select the latest VDDK version and click Download.
  4. Save the VDDK archive file in the temporary directory.

  5. Extract the VDDK archive: 

    $ tar -xzf VMware-vix-disklib-<version>.x86_64.tar.gz

  6. Create a Dockerfile: 

    $ cat > Dockerfile <<EOF
FROM registry.access.redhat.com/ubi8/ubi-minimal
COPY vmware-vix-disklib-distrib /vmware-vix-disklib-distrib
RUN mkdir -p /opt
ENTRYPOINT ["cp", "-r", "/vmware-vix-disklib-distrib", "/opt"]
EOF

  7. Build the VDDK image: 

    $ podman build . -t <registry_route_or_server_path>/vddk:<tag>

  8. Push the VDDK image to the registry: 

    $ podman push <registry_route_or_server_path>/vddk:<tag>
  9. Ensure that the image is accessible to your OpenShift Virtualization environment.

2.6.2. Obtaining the SHA-1 fingerprint of a vCenter host

You must obtain the SHA-1 fingerprint of a vCenter host in order to create a Secret CR.

Procedure

  • Run the following command: 

    $ openssl s_client \
    -connect <vcenter_host>:443 \ 1
    < /dev/null 2>/dev/null \
    | openssl x509 -fingerprint -noout -in /dev/stdin \
    | cut -d '=' -f 2
    1
    Specify the IP address or FQDN of the vCenter host.

    Example output

    01:23:45:67:89:AB:CD:EF:01:23:45:67:89:AB:CD:EF:01:23:45:67

2.6.3. Increasing the NFC service memory of an ESXi host

If you are migrating more than 10 VMs from an ESXi host in the same migration plan, you must increase the NFC service memory of the host. Otherwise,the migration will fail because the NFC service memory is limited to 10 parallel connections.

Procedure

  1. Log in to the ESXi host as root.

  2. Change the value of maxMemory to 1000000000 in /etc/vmware/hostd/config.xml: 

    ...
      <nfcsvc>
         <path>libnfcsvc.so</path>
         <enabled>true</enabled>
         <maxMemory>1000000000</maxMemory>
         <maxStreamMemory>10485760</maxStreamMemory>
      </nfcsvc>
...

  3. Restart hostd: 

    # /etc/init.d/hostd restart

    You do not need to reboot the host.

2.7. Software compatibility guidelines

You must install compatible software versions.

Table 2.4. Compatible software versions

Migration Toolkit for VirtualizationOpenShift Container PlatformOpenShift VirtualizationVMware vSphereRed Hat Virtualization

2.2

4.9

4.9.1

6.5 or later

4.3 or later