Adding DRBD as a PCS cluster resource

You will recall how in Chapter 2, Installing Cluster Services and Configuring Network Components, we added a virtual IP address to the cluster. Now, it's time to do the same with the DRBD resource that we have just created and configured.

Before doing that, however, we must point out that one of the most distinguishing features of the PCS command-line tool that we first introduced back in Chapter 2, Installing Cluster Services and Configuring Network Components, is its ability to save the current cluster configuration to a file, to which you can add further settings using command-line tools. Then, you can use the resulting file to update the running cluster configuration.

To retrieve the cluster configuration from the Cluster Information Base (CIB) and save it to a file named drbd0_conf in the current working directory, use the following command to make sure you started the cluster first:

pcs cluster start --all

Then save the cluster configuration to the...