The SmartConnect Service IP (SSIP) service is updated for OneFS 8.2; this section is specific to releases prior to OneFS 8.2. For more information about the SSIP in OneFS 8.2, see SmartConnect Multi-SSIP.

The PowerScale clustered compute, and storage platform has no single point of failure. However, the SmartConnect DNS service must be active on only one node at any time, per subnet. The SmartConnect Service IP resides on the node with the lowest node ID that has an interface in the given subnet, not necessarily on the node with the lowest Logical Node Number (LNN) in the cluster.

To illustrate how this works, suppose that an existing four-node cluster is refreshed with four new nodes. Assume that the cluster has only one configured subnet, all the nodes are on the network, and that there are sufficient IP addresses to handle the refresh. The first step in the cluster refresh is to add the new nodes with the existing nodes, temporarily creating an eight-node cluster. Next, the original four nodes are SmartFailed. The cluster is then composed of the four new nodes with the original dataset.

As the administrators perform the refresh, they check the current configuration using the isi config command, with the status advanced command, as shown in the following example:

isi config

>status advanced

The SmartConnect service continues to run throughout the process as the existing nodes are refreshed. The following example illustrates where the SmartConnect service runs at each step in the refresh process.

Once the four new nodes are added to the cluster, based on the existing naming convention, they are automatically named clustername-5, clustername-6, clustername-7, and clustername-8. The following table shows the Node IDs and LNNs:

Table 5.      8-node cluster configuration, before SmartFail

Note: The SmartConnect service always runs on the node with the lowest node ID; here, NodeID 1 is mapping to LNN 1.

Next, the original nodes are removed using SmartFail. The updated Node IDs and LNNs are displayed in the following table:

Table 6.      4-node cluster configuration, after SmartFail

Note: The SmartConnect service always runs on the node with the lowest node ID; here, NodeID 5 is mapping to LNN 1.

Keeping the naming convention consistent, the administrators rename the new nodes, formerly clustername- 5, clustername-6, clustername-7, and clustername-8, to clustername-1, clustername-2, clustername-3, and clustername-4, respectively. The updated Node IDs and LNNs remain the same, but map to a different Node Name, as displayed in the following table:

Table 7.      4-node cluster configuration—after rename

Note: The SmartConnect service always runs on the node with the lowest node ID; here, NodeID 5 is mapping to LNN 1.

If LNN 1 is offline for maintenance, the SmartConnect service migrates to LNN 2, because LNN 2 has the next lowest NodeID number, 6.