remote failover of VLAN interfaces when failure is detected. Failure of a VLAN interface is typically the result of the failure of the underlying physical NIC port or aggregated (APA) ports.

Configuration Restrictions

HP-UX allows up to 1024 VLANs to be created from a physical NIC port. A large pool of system resources is required to accommodate such a configuration; Serviceguard could suffer performance degradation if many network interfaces are configured in each cluster node. To prevent this and other problems, Serviceguard imposes the following restrictions:

A maximum of 30 network interfaces per node is supported. The interfaces can be physical NIC ports, VLAN interfaces, APA aggregates, or any combination of these.

Local failover of VLANs must be onto the same link types. For example, you must fail over from VLAN-over-Ethernet to VLAN-over-Ethernet.

The primary and standby VLANs must have same VLAN ID (or tag ID).

VLAN configurations are only supported on HP-UX 11i releases.

Only port-based and IP-subnet-based VLANs are supported. Protocol-based VLAN is not supported because Serviceguard does not support any transport protocols other than TCP/IP.

Each VLAN interface must be assigned an IP address in a unique subnet, unless it is a standby for a primary VLAN interface.

Failover from physical LAN interfaces to VLAN interfaces or vice versa is not supported because of restrictions in VLAN software.

Using VLAN in a Wide Area Network cluster is not supported.

If CVM disk groups are used, you must not configure the Serviceguard heartbeat over VLAN interfaces.

Additional Heartbeat Requirements

VLAN technology allows great flexibility in network configuration. To maintain Serviceguard’s reliability and availability in such an environment, the heartbeat rules are tightened as follows when the cluster is using VLANs:

1.VLAN heartbeat networks must be configured on separate physical NICs or APA aggregates, to avoid single points of failure.

2.Heartbeats are still recommended on all cluster networks, including VLANs.

3.If you are using VLANs, but decide not to use VLANs for heartbeat networks, heartbeats are recommended for all other physical networks or APA aggregates specified in the cluster configuration file.

Volume Managers for Data Storage

A volume manager is a tool that lets you create units of disk storage known as storage groups. Storage groups contain logical volumes for use on single systems and in high availability clusters. In Serviceguard clusters, storage groups are activated by package control scripts.

Types of Redundant Storage

In Serviceguard, there are two types of supported shared data storage: mirrored individual disks (also known as JBODs, for “just a bunch of disks”), and external disk arrays which configure

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HP Serviceguard manual Volume Managers for Data Storage, Types of Redundant Storage, Configuration Restrictions