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Setting up the private network

VCS requires you to setup a private network between the systems that will form part of a cluster.

 To set up the private network

1. Install the required network interface cards (NICs).
2. Connect the VCS private Ethernet controllers on each system.
3. Use cross-over Ethernet cables (supported only on two systems), or independent hubs, for each VCS communication network. Ensure that power to the hubs comes from separate sources. On each system, use two independent network cards to provide redundancy.

   During the process of setting up heartbeat connections, note that a chance for data corruption exists if a failure removes all communications between the systems and still leaves the systems running and capable of accessing shared storage.

   Private network setups: two-node and four-node clusters

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4. Configure the Ethernet devices used for the private network such that the auto-negotiation protocol is not used. This ensures a more stable configuration with cross-over cables.

   You can achieve this either by editing the /etc/system file to disable auto-negotiation on all Ethernet devices system-wide or by creating a qfe.conf file in the /kernel/drv directory to disable auto-negotiation for the individual devices used for private network. Refer to the Sun Ethernet driver product documentation for information on these methods.

5. Test network connections by temporarily assigning network addresses and use telnet or ping to verify communications.

   LLT uses its own protocol, and does not use TCP/IP. Therefore, to ensure the private network connections are used only for LLT communication and not for TCP/IP traffic, unplumb and unconfigure the temporary addresses after testing.

   The installvcs program configures the private network in the cluster during installation.

   See Installing and configuring VCS.

   More information about configuring LLT for the private network links is in the manual installation chapter.

   See Manually installing and configuring VCS.

Using network switches

You can use network switches instead of hubs. However, by default, Sun systems assign the same MAC address to all interfaces. Thus, connecting two or more interfaces to a network switch can cause problems. For example, if IP is configured on one interface and LLT on another, and both interfaces are connected to a switch (assuming separate VLANs), the duplicate MAC address on the two switch ports can cause the switch to incorrectly redirect IP traffic to the LLT interface and vice-versa. To avoid this, configure the system to assign unique MAC addresses by setting the eeprom(1M) parameter local-mac-address to true.

  Note   Because of their performance characteristics, network switches are recommended for clusters supporting the Veritas Storage Foundation Cluster File System and Veritas Storage Foundation for Oracle RAC, which make extensive use of the private cluster interconnects for distributed locking. See the Veritas Cluster Server User's Guide and review the chapter on VCS performance considerations.