Changing Data Center and Cluster Compatibility Versions After Upgrading

Oracle Linux Virtualization Manager data centers and clusters have a compatibility version. The data center compatibility version indicates the version of Oracle Linux Virtualization Manager that the data center is intended to be compatible with. The cluster compatibility version indicates the features supported by all of the hosts in the cluster. The cluster compatibility is set according to the version of the least capable host operating system in the cluster.

The preferred approach after upgrading your engine to 4.5 is to upgrade all hosts to 4.5 and then change the cluster compatibility to 4.7. You can then add new hosts as 4.5 hosts.

Important:

Although the Oracle Linux Virtualization Manager version is 4.5, the corresponding compatibility version is 4.7.

Compatibility Version Restrictions

Consider these restrictions to ensure you do not have issues with compatibility versions after you upgrade.

Data Center Compatibility Versions

The data center compatibility level is the minimum version you can use for all clusters in your data center. For example:

If your data center compatibility level is 4.7, you can only have clusters with compatibility level 4.7.
If your data center compatibility level is 4.4, you can have 4.4 or higher compatibility level clusters.

Cluster Compatibility Versions

The cluster compatibility level is the minimum version of any host you add to the cluster. For example:

If you have a 4.6 compatibility version cluster, you can add 4.4 or 4.5 hosts.
If you have a 4.7 compatibility version cluster, you can only add 4.5 hosts.

Possible Errors When Changing Compatibility Versions

If you try to change the data center compatibility version from 4.6 to 4.7 when you have a 4.4 compatibility version cluster, you get the following error:

Cannot update Data Center compatibility version to a value that is greater than its 
cluster's version. The following clusters should be upgraded: [clustername]

If you try to change the cluster compatibility version from 4.6 to 4.7 when you have 4.4 hosts running, you get the following error:

Error while executing action: Cannot change Cluster Compatibility Version to higher version 
when there are active Hosts with lower version. -Please move Host [hostname] with lower 
version to maintenance first.

When you put a 4.4 host in maintenance mode, you can change the cluster and then data center compatibility version to 4.7. However, the host shows non-operational with the following event:
```
Host [hostname] is compatible with versions ([version levels]) and cannot join Cluster 
[clustername] which is set to version [version level].
```

Changing Cluster Compatibility Versions

To change the cluster compatibility version, you must have first upgraded all the hosts in your cluster to a level that supports your desired compatibility level.

Verify all hosts are running a version level that supports your desired compatibility level. See Compatibility Version Restrictions.
In the Administration Portal, go to Compute and click Clusters.
Select the cluster to change and click Edit.
From the Edit Cluster dialog box, select General.
For Compatibility Version, select desired value and click OK.
On the Change Cluster Compatibility Version confirmation window, click OK.

Important:

You might get an error message warning that some virtual machines and templates are incorrectly configured. To fix this error, edit each virtual machine manually. The Edit Virtual Machine window provides additional validations and warnings that show what to correct. Sometimes the issue is automatically corrected and the virtual machine’s configuration just needs to be saved again. After editing each virtual machine, you will be able to change the cluster compatibility version.
Update the cluster compatibility version of all running or suspended virtual machines by restarting them from within the Administration Portal.

Note:

Virtual machines continue to run in the previous cluster compatibility level until you restart them. The Next-Run icon (triangle with an exclamation mark) indentifies virtual machines that require a restart. However, the self-hosted engine virtual machine does not need to be restarted.

You cannot change the cluster compatibility version of a virtual machine snapshot that is in preview. You must first commit or undo the preview.

Changing Data Center Compatibility Versions

After updating the compatibility version of all clusters in a data center, you can change the compatibility version of the data center itself.

Verify that all clusters are at the proper compatibility version. If not, change the version of the clusters, see Changing Cluster Compatibility Versions.
In the Administration Portal, go to Compute and click Data Centers.
Select the data center to change and click Edit.
From the Edit Data Center dialog box, change the Compatibility Version to the desired value and then click OK.
On the Change Data Center Compatibility Version confirmation window, click OK.