13.1 Requirements for Creating Linux POSIX Volume Cluster Resources

Your system must meet the requirements in this section in addition to the cluster requirements described in Section 4.0, Planning for Novell Cluster Services.

13.1.1 Novell Cluster Services

Novell Cluster Services must be installed and running when you create and manage the shared Linux POSIX volume. The cluster must be active.

13.1.2 EVMS

The EVMS (Enterprise Volume Management System) is installed automatically when you install Novell Cluster Services. When you configure Novell Cluster Services on a server, the Cluster Segment Manager (CSM) plug-in for EVMS is installed in EVMS. This setup is required to be completed before you can configure Linux POSIX volumes for use with Novell Cluster Services.

WARNING:EVMS administration utilities (evms, evmsgui, and evmsn) should not be running when they are not being used. EVMS utilities lock the EVMS engine, which prevents other EVMS-related actions from being performed. This affects both NSS and Linux POSIX volume actions.

NSS and Linux POSIX volume cluster resources should not be migrated while any of the EVMS administration utilities are running.

For information about using EVMS, see Using EVMS to Manage Devices in the SLES 10 SP3/SP4 Storage Administration Guide, or see the EVMS man page by entering man evms at a terminal console.

13.1.3 Cluster Segment Manager

Novell Cluster Services uses the Cluster Segment Manager (CSM) plug-in to EVMS in order to manage shared devices. The CSM allows only one node at a time to access a shared cluster resource. This helps prevent the potential data corruption that can occur if multiple nodes concurrently access the same data.

The CSM plug-in to EVMS is required to create a container on the shared device where you will create the Linux POSIX volume.

The Cluster Segment Manager requires use of the entire disk (or LUN).

CSM containers require Novell Cluster Services to be running on all nodes that access the cluster resources on OES 2 Linux.

IMPORTANT:Do not create or make to modifications to any shared EVMS objects unless Novell Cluster Services is running.

13.1.4 Shareable Device

You should carefully plan how you want to configure your shared storage prior to configuring the Linux POSIX cluster resource. For planning information, see the following:

For the Linux POSIX volume, you need an unpartitioned disk or LUN that is connected via Fibre Channel or iSCSI protocols to the OES 2 Linux server. The disk or LUN must be able to be managed by EVMS.

You must install and configure Novell Cluster Services on a server before you can configure the storage device as shareable for clustering.

13.1.5 Journaled Linux POSIX File Systems

Novell Cluster Services supports cluster-enabling EVMS partitions and volumes for any journaled Linux POSIX file systems (such as Ext3, ReiserFS, and XFS).

13.1.6 Resource IP Address

Each Linux POSIX cluster resource needs a unique static IP address that is in the same subnet as the IP addresses that are used for the cluster and cluster nodes. The IP address is used to provide access and failover capability for the cluster-enabled volume.

13.1.7 Mixed-Node Clusters

A mixed-node cluster is supported as a temporary configuration scenario for converting a cluster from NetWare 6.5 SP8 to OES 2 Linux or for upgrading a cluster from OES 1 Linux to OES 2 Linux. You can create new Linux POSIX cluster resources on the OES 2 Linux nodes in order to support the migration of services and data from the old nodes to the new OES 2 Linux (or later) nodes. However, the new cluster resources should be cluster migrated or failed over only between the OES 2 Linux nodes.

13.1.8 Novell Samba

Novell Samba is supported for Linux POSIX volume cluster resources. It can be set up after you cluster-enable the volume. For information about setting up Novell Samba for storage resources, see Configuring Samba for Novell Cluster Services in the OES2 SP3: Samba Administration Guide.