Your system must meet the requirements in this section in addition to the cluster requirements described in Section 4.0, Planning for OES Cluster Services.
OES Cluster Services must be installed, configured, and running when you create and manage the shared LVM volume group and logical volume. The cluster must be active.
The Linux Logical Volume Manager (LVM) 2 software supports LVM volume groups and logical volumes. LVM2 must be installed and running on each node in the cluster. LVM2 runs automatically on OES 11 and later servers; no separate installation or setup is required.
The Linux Clustered Volume Manager Daemon (CLVMD, clvmd) software allows you to exclusively mount a shared volume group on one node at a time in a cluster. It distributes the LVM metadata updates around a cluster. CLVM must be installed and running on each node in the cluster. CLVMD runs automatically on OES 11 and later servers; no separate installation or setup is required.
IMPORTANT:Ensure that you have installed the latest patches for SUSE Linux Enterprise Server 12 SP2. Clustered LVM volume groups require Linux kernel version 184.108.40.206-0.3 or later.
Each cluster resource requires 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.
The shared SAN storage device that you use for an LVM volume group cluster resource must be initialized and have no partitions on it. When the device is used in a cluster resource, LVM uses the entire device for the volume group. Ensure that you size your LUNs accordingly. Use the SAN management tools to assign the LUN to all nodes in the cluster.
IMPORTANT:If you use NSS management tools to manage devices, do not enable the Shareable for Clustering option. Doing so adds a 4 KB partition to the device, which makes it unavailable to LVM.
LVM requires the presence of all the nodes in the cluster to modify the metadata on shared storage. This allows LVM to get the exclusive locks it needs to perform actions on shared storage.
Before you attempt to create or modify LVM volume group cluster resources:
All of the nodes must be joined in the cluster and running properly.
The clvmd daemon must be running on all nodes.
OES NCP Server can be used to provide NCP file access to Linux POSIX file systems on OES servers. Its NCP volumes feature can be used to provide NCP access to files on an LVM volume group cluster resource. NCP Server must be installed, configured, and running on each node in the cluster.
NCP volume names can be up to 14 alphanumeric characters, using uppercase letters A through Z and numbers 0 through 9. Underscores (_) are allowed.
If you NCP enable a Linux volume as you create it with NSSMU or the nlvm create linux volume command, the NCP volume name uses the specified Linux volume name, but all letters are uppercase. NCP treats the Linux volume name as case insensitive. Ensure that the specified Linux volume name does not exceed 14 characters, does not use special characters, and is unique across all nodes in the cluster for both Linux and NCP.
You can configure NCP file access for an LVM volume group cluster resource when you create the resource by using NSSMU or the nlvm create linux volume command. With the NCP option enabled, these tools automatically add commands to the resource scripts that mount, dismount, and monitor an NCP volume. The NCP volume is named the same as the LVM logical volume name, and all letters in the name are uppercase. The tools automatically create an NCP Virtual Server object for the volume group cluster resource.
You can create an NCP Virtual Server object for the LVM cluster resource to make the resource visible in the eDirectory tree. The virtual server alone does not provide NCP file access.
You can add NCP file access support to an existing LVM cluster resource by creating an NCP Volume object and adding commands to the scripts to manage the volume. For details about setting up NCP volumes on an existing clustered Linux volume, see OES 2018 SP3: NCP Server for Linux Administration Guide.
You can provide native Linux file access to files on an LVM volume group cluster resource for eDirectory users who are enabled for Linux User Management (LUM). The Linux file access protocols must also be LUM enabled on each node of the cluster. For information about LUM-enabling your eDirectory users and native Linux file access protocols, see the OES 2018 SP3: Linux User Management Administration Guide.