Sun Cluster 3.1 System Administration Guide

Administering the Public Network

Sun Cluster 3.1 supports the Solaris implementation of Internet Protocol (IP) Network Multipathing for public networks. Basic IP Network Multipathing administration is the same for both cluster and non-cluster environments. Multipathing administration is covered in the appropriate Solaris documentation. However, review the guidelines that follow before administering IP Network Multipathing in a Sun Cluster environment.

How to Administer IP Network Multipathing Groups in a Cluster

Before performing IP Network Multipathing procedures on a cluster, consider the guidelines below.

Each public network adapter must belong to a multipathing group.
The local-mac-address? variable must have a value of true for Ethernet adapters.
You must configure a test IP address for each multipathing group adapter.
Test IP addresses for all adapters in the same multipathing group must belong to a single IP subnet.
Test IP addresses must not be used by normal applications because they are not highly available.
There are no restrictions on multipathing group naming. However, when configuring a resource group, the netiflist naming convention is any multipathing name followed by either the nodeID number or the node name. For example, given a multipathing group named sc_ipmp0, the netiflist naming could be either sc_ipmp0@1 or sc_ipmp0@phys-schost-1, where the adapter is on the node phys-schost-1 which has the nodeID of 1.
Avoid unconfiguring (unplumbing) or bringing down an adapter of an IP Network Multipathing group without first switching over the IP addresses from the adapter to be removed to an alternate adapter in the group, using the if_mpadm(1M) command.
Avoid rewiring adapters to different subnets without first removing them from their respective multipathing groups.
Logical adapter operations can be done on an adapter even if monitoring is on for the multipathing group.
You must maintain at least one public network connection for each node in the cluster. The cluster is inaccessible without a public network connection.
To view the status of IP Network Multipathing groups on a cluster, use the command scstat(1M) with the -i option.

For more information about IP Network Multipathing, see the appropriate documentation in the Solaris system administration documentation set.

Table 5–3 Task Map: Administering the Public Network


Solaris Operating Environment Release	For Instructions, Go To...
Solaris 8 operating environment	IP Network Multipathing Administration Guide
Solaris 9 operating environment	“IP Network Multipathing Topics” inSystem Administration Guide: IP Series

For cluster software installation procedures, see the Sun Cluster 3.1 Software Installation Guide. For procedures about servicing public networking hardware components, see the Sun Cluster 3.1 Hardware Administration Manual.

Dynamic Reconfiguration With Public Network Interfaces

There are a few issues you must consider when completing dynamic reconfiguration (DR) operations on public network interfaces in a cluster.

All of the requirements, procedures, and restrictions that are documented for the Solaris DR feature also apply to Sun Cluster DR support (except for the operating environment quiescence operation). Therefore, review the documentation for the Solaris DR feature before using the DR feature with Sun Cluster software. You should review in particular the issues that affect non-network IO devices during a DR detach operation.
DR remove-board operations can succeed only when public network interfaces are not active. Before removing an active public network interface, switch the IP addresses from the adapter to be removed to another adapter in the multipathing group, using the if_mpadm(1M) command.
If you try to remove a public network interface card without having properly disabled it as an active network interface, Sun Cluster rejects the operation and identifies the interface that would be affected by the operation.

Caution –

For multipathing groups with two adapters, if the remaining network adapter fails while you are performing the DR remove operation on the disabled network adapter, availability is impacted. The remaining adapter has no place to fail over for the duration of the DR operation.

Complete the following procedures in the order indicated when performing DR operations on public network interfaces.

Table 5–4 Task Map: Dynamic Reconfiguration with Public Network Interfaces


Task	For Instructions, Go To...
1. Switch the IP addresses from the adapter to be removed to another adapter in the multipathing group, using the `if_mpadm`.	if_mpadm(1M) man page. The appropriate Solaris documentation: Solaris 8: IP Network Multipathing Administration Guide Solaris 9: “IP Network Multipathing Topics” in System Administration Guide: IP Services
2. Remove the adapter from the multipathing group using the `ifconfig` command.	The appropriate Solaris documentation: Solaris 8: IP Network Multipathing Administration Guide Solaris 9: “IP Network Multipathing Topics” in System Administration Guide: IP Services ifconfig(1M) man page
3. Perform the DR operation on the public network interface.	Sun Enterprise 10000 DR Configuration Guide and the Sun Enterprise 10000 Dynamic Reconfiguration Reference Manual (from the Solaris 8 on Sun Hardware and Solaris 9 on Sun Hardware collections)