HP ProLiant DL585 G2 Storage-Server - Manual (Page 101)

• Physical Disk resources are placed in a cluster group and relate to the basic disk. When a Physical
Disk resource is created through Cluster Administrator, the resource should be inserted into an
existing cluster group or a corresponding group should be created for the resource to reside in.
• File share resources are placed in a group and relate to the actual directory on the drive on
which the share is being created.
• An IP Address resource is formed in the group and relates to the IP address by which the group's
virtual server is identified on the network.
• A Network Name resource is formed in the group and relates to the name published on the
network by which the group is identified.
• The Group is owned by one of the nodes of the cluster, but may transition to the other nodes
during failover conditions.
The diagram illustrates a cluster containing two nodes. Each node has ownership of one group.
Contained within each group are file shares that are known on the network by the associated Network
Name and IP address. In the specific case of Node1, file share Eng1 relates to E:\Eng1. This file share
is known on the network as \\Fileserver1\Eng1 with an IP address of 172.18.1.99.
For cluster resources to function properly, two very important requirements should be adhered to:
• Dependencies between resources of a group must be established. Dependencies determine the
order of startup when a group comes online. In the above case, the following order should
be maintained:
1. File Share—Dependent on Physical Disk Resource and Network Name
2. Network Name—Dependent on IP Address
Failure to indicate the dependencies of a resource properly may result in the file share attempting to
come online prior to the physical disk resource being available, resulting in a failed file share.
• Groups should have a Network Name resource and an IP Address resource. These resources
are used by the network to give each group a virtual name. Without this virtual reference to the
group, the only way to address a share that is created as a clustered resource is by node name.
Physical node names do not transition during a failover, whereas virtual names do.
For example, if a client maps a network share to \\Node1\Eng1 instead of \\Fileserver1\Eng1, when
Node1 fails and Node2 assumes ownership, the map will become invalid because the reference in the
map is to \\Node1. If the map were created to the virtual name and Node1 were to fail, the map would
still exist when the group associated with Eng1 failed over to Node2.
The previous diagram is an example and is not intended to imply limitations of a single group or node.
Groups can contain multiple physical disks resources and file shares and nodes can have multiple
groups, as shown by the group owned by Node2.
Cluster planning
Requirements for taking advantage of clustering include:
• Storage planning
• Network planning
• Protocol planning
Storage planning
For clustering, a basic disk must be designated for the cluster and configured as the Quorum disk.
Additional basic disks are presented to each cluster node for data storage as physical disk resources.
The physical disk resources are required for the basic disks to successfully work in a cluster environment,
protecting it from simultaneous access from each node.
The basic disk must be added as a physical disk resource to an existing cluster group or a new cluster
group needs to be created for the resource. Cluster groups can contain more than one physical disk
resource depending on the site-specific requirements.
HP ProLiant Storage Server 101