Why does cman fail to start with the error "Cannot start, ais may already be running /usr/sbin/cman_tool: aisexec daemon didn't start"?

In order for aisexec to start properly, the cluster's name must be less than 15 characters. A cluster configured with the following line

<cluster alias="Red_Hat_Test_Cluster" config_version="20" name="Red_Hat_Test_Cluster">

would produce this error when starting cman

[root@node2 ~]# service cman start
Starting cluster: 
 Loading modules... do...