Sun Cluster Software Installation Guide for Solaris OS

Sun Cluster Configurable Components

This section provides guidelines for the following Sun Cluster components that you configure:

Add this information to the appropriate configuration planning worksheet.

Global-Cluster Name

Specify a name for the global cluster during Sun Cluster configuration. The global cluster name should be unique throughout the enterprise.

For information about naming a zone cluster, see Zone Clusters.

Global-Cluster Voting-Node Names

The name of a voting node in a global cluster is the same name that you assign to the physical or virtual host when you install it with the Solaris OS. See the hosts(4) man page for information about naming requirements.

In single-host cluster installations, the default cluster name is the name of the voting node.

During Sun Cluster configuration, you specify the names of all voting nodes that you are installing in the global cluster.

For information about node names in a zone cluster, see Zone Clusters.

Zone Names

On the Solaris 10 OS in versions that support Solaris brands, a non-global zone of brand native is a valid potential node of a resource-group node list. Use the naming convention nodename:zonename to specify a non-global zone to a Sun Cluster command.

To specify the global zone, you need to specify only the voting-node name.

For information about a cluster of non-global zones, see Zone Clusters.

Private Network

Note –

You do not need to configure a private network for a single-host global cluster. The scinstall utility automatically assigns the default private-network address and netmask, even though a private network is not used by the cluster.

Sun Cluster software uses the private network for internal communication among nodes and among non-global zones that are managed by Sun Cluster software. A Sun Cluster configuration requires at least two connections to the cluster interconnect on the private network. When you configure Sun Cluster software on the first node of the cluster, you specify the private-network address and netmask in one of the following ways:

If you choose to specify a different netmask, the scinstall utility prompts you for the number of nodes and the number of private networks that you want the IP address range to support. On the Solaris 10 OS, the utility also prompts you for the number of zone clusters that you want to support. The number of global-cluster nodes that you specify should also include the expected number of unclustered non-global zones that will use the private network.

The utility calculates the netmask for the minimum IP address range that will support the number of nodes, zone clusters, and private networks that you specified. The calculated netmask might support more than the supplied number of nodes, including non-global zones, zone clusters, and private networks. The scinstall utility also calculates a second netmask that would be the minimum to support twice the number of nodes, zone clusters, and private networks. This second netmask would enable the cluster to accommodate future growth without the need to reconfigure the IP address range.

The utility then asks you what netmask to choose. You can specify either of the calculated netmasks or provide a different one. The netmask that you specify must minimally support the number of nodes and private networks that you specified to the utility.

Note –

Changing the cluster private IP-address range might be necessary to support the addition of voting nodes, non-global zones, zone clusters, or private networks.

To change the private-network address and netmask after the cluster is established, see How to Change the Private Network Address or Address Range of an Existing Cluster in Sun Cluster System Administration Guide for Solaris OS. You must bring down the cluster to make these changes.

However, on the Solaris 10 OS the cluster can remain in cluster mode if you use the cluster set-netprops command to change only the netmask. For any zone cluster that is already configured in the cluster, the private IP subnets and the corresponding private IP addresses that are allocated for that zone cluster will also be updated.

If you specify a private-network address other than the default, the address must meet the following requirements:

See Planning Your TCP/IP Network (Tasks), in System Administration Guide: IP Services (Solaris 9 or Solaris 10) for more information about private networks.

Private Hostnames

The private hostname is the name that is used for internode communication over the private-network interface. Private hostnames are automatically created during Sun Cluster configuration of a global cluster or a zone cluster. These private hostnames follow the naming convention clusternodenodeid -priv, where nodeid is the numeral of the internal node ID. During Sun Cluster configuration, the node ID number is automatically assigned to each voting node when the node becomes a cluster member. A voting node of the global cluster and a node of a zone cluster can both have the same private hostname, but each hostname resolves to a different private-network IP address.

After a global cluster is configured, you can rename its private hostnames by using the clsetup(1CL) utility. Currently, you cannot rename the private hostname of a zone-cluster node.

For the Solaris 10 OS, the creation of a private hostname for a non-global zone is optional. There is no required naming convention for the private hostname of a non-global zone.

Cluster Interconnect

The cluster interconnects provide the hardware pathways for private-network communication between cluster nodes. Each interconnect consists of a cable that is connected in one of the following ways:

For more information about the purpose and function of the cluster interconnect, see Cluster Interconnect in Sun Cluster Concepts Guide for Solaris OS.

Note –

You do not need to configure a cluster interconnect for a single-host cluster. However, if you anticipate eventually adding more voting nodes to a single-host cluster configuration, you might want to configure the cluster interconnect for future use.

During Sun Cluster configuration, you specify configuration information for one or two cluster interconnects.

You can configure additional cluster interconnects, up to six interconnects total, after the cluster is established by using the clsetup(1CL) utility.

For guidelines about cluster interconnect hardware, see Interconnect Requirements and Restrictions in Sun Cluster 3.1 - 3.2 Hardware Administration Manual for Solaris OS. For general information about the cluster interconnect, see Cluster-Interconnect Components in Sun Cluster Overview for Solaris OS and Sun Cluster Concepts Guide for Solaris OS.

Transport Adapters

For the transport adapters, such as ports on network interfaces, specify the transport adapter names and transport type. If your configuration is a two-host cluster, you also specify whether your interconnect is a point-to-point connection (adapter to adapter) or uses a transport switch.

Consider the following guidelines and restrictions:

See the scconf_trans_adap_*(1M) family of man pages for information about a specific transport adapter.

Transport Switches

If you use transport switches, such as a network switch, specify a transport switch name for each interconnect. You can use the default name switchN, where N is a number that is automatically assigned during configuration, or create another name.

Also specify the switch port name or accept the default name. The default port name is the same as the internal node ID number of the Solaris host that hosts the adapter end of the cable. However, you cannot use the default port name for certain adapter types, such as SCI-PCI.

Note –

Clusters with three or more voting nodes must use transport switches. Direct connection between voting cluster nodes is supported only for two-host clusters.

If your two-host cluster is direct connected, you can still specify a transport switch for the interconnect.

Tip –

If you specify a transport switch, you can more easily add another voting node to the cluster in the future.

Global Fencing

Fencing is a mechanism that is used by the cluster to protect the data integrity of a shared disk during split-brain situations. By default, the scinstall utility in Typical Mode leaves global fencing enabled, and each shared disk in the configuration uses the default global fencing setting of pathcount. With the pathcount setting, the fencing protocol for each shared disk is chosen based on the number of DID paths that are attached to the disk.

In Custom Mode, the scinstall utility prompts you whether to disable global fencing. For most situations, respond No to keep global fencing enabled. However, you can disable global fencing to support the following situations:

Caution – Caution –

If you disable fencing under other situations than the following, your data might be vulnerable to corruption during application failover. Examine this data corruption possibility carefully when you consider turning off fencing.

If you disable global fencing during cluster configuration, fencing is turned off for all shared disks in the cluster. After the cluster is configured, you can change the global fencing protocol or override the fencing protocol of individual shared disks. However, to change the fencing protocol of a quorum device, you must first unconfigure the quorum device. Then set the new fencing protocol of the disk and reconfigure it as a quorum device.

For more information about fencing behavior, see Failfast Mechanism in Sun Cluster Concepts Guide for Solaris OS. For more information about setting the fencing protocol of individual shared disks, see the cldevice(1CL) man page. For more information about the global fencing setting, see the cluster(1CL) man page.

Quorum Devices

Sun Cluster configurations use quorum devices to maintain data and resource integrity. If the cluster temporarily loses connection to a voting node, the quorum device prevents amnesia or split-brain problems when the voting cluster node attempts to rejoin the cluster. For more information about the purpose and function of quorum devices, see Quorum and Quorum Devices in Sun Cluster Concepts Guide for Solaris OS.

During Sun Cluster installation of a two-host cluster, you can choose to let the scinstall utility automatically configure as a quorum device an available shared disk in the configuration. Shared disks include any Sun NAS device that is configured for use as a shared disk. The scinstall utility assumes that all available shared disks are supported as quorum devices.

If you want to use a quorum server or a Network Appliance NAS device as the quorum device, you configure it after scinstall processing is completed.

After installation, you can also configure additional quorum devices by using the clsetup(1CL) utility.

Note –

You do not need to configure quorum devices for a single-host cluster.

If your cluster configuration includes third-party shared storage devices that are not supported for use as quorum devices, you must use the clsetup utility to configure quorum manually.

Consider the following points when you plan quorum devices.

For more information about quorum devices, see Quorum and Quorum Devices in Sun Cluster Concepts Guide for Solaris OS and Quorum Devices in Sun Cluster Overview for Solaris OS.