9.2 Volumes in a Cluster

In a cluster setup, when a Macintosh client connects to the physical IP of the AFP server, both the local volumes and the cluster-enabled shared volumes are exported to the client.

However, if the client connects to the cluster/virtual IP, then only the cluster-enabled shared volumes associated with the cluster IP are exported.

For example, consider a cluster setup with two AFP servers running on nodes A and B. If the cluster resource is bound to node A, a Mac client connecting to the physical IP of node A can access both the local and the cluster-enabled shared volumes.

If the client connects to the physical IP of node B, then only local volumes on node B are exported, because the cluster resource is now on node A. However, if the cluster resource moves to node B because of migration or failover, then clients connecting to node B can see both local and shared volumes.

NSS volumes are identified by the machine name and volume name combination. For instance, if you create a volume titled AFP_Volume on a server named ACME, the volume is represented as ACME.AFP_Volume. The Volume Name Management feature helps you specify an alternate name for the NSS volume. For instance, you can rename ACME.AFP_Volume to AFP_Volume. This is mandatory in a cluster setup where you need to identify volumes without the machine name prefix

The following example illustrates how cluster nodes map to shared volumes.

   Example 3: Renaming cluster volumes
   afpvols.conf for serverA:
   serverA.vol1       sharedVol1
   serverA.vol2       sharedVol2

   afpvols.conf for serverB:

   serverB.vol1       sharedVol1
   serverB.vol2       sharedVol2

9.2.1 Volume Name Management in a Cluster

Volume management is done in two ways in a cluster:

  • By using the iManager AFP Management plug-in:

    The iManager AFP Management plug-in requires a volume to be locally mounted on the cluster node before adding it to the AFP configuration. You migrate the volume resource to each node and usethe iManager AFP Management plug-in to add the volume to the AFP configuration.

  • By editing the /etc/opt/novell/afptcpd/afpvols.conf on each cluster node. This is done without migrating the resource to each node. Use the following syntax: ServerName.VolumeName VolumeName.

    Replace ServerName with the host name of the local cluster node and replace VolumeName with the name of the shared, cluster-enabled volume.