HP ProLiant DL380 G5 DPSS, Administration Manual

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NOTE:
Only the Quorum disk should be accessible by the new node. The new node should not have access to
the other LUNs in the cluster until after it has joined the cluster. After the node has joined the cluster, the
LUNs may be presented to the new node. Move the physical disk resources over to the new node to
con fi rm functionality.
CAUTION:
Presenting other LUNs to the non-clustered system could lead to data corruption.
Geographically dispersed clusters
Cluster nodes can be geographically dispersed to provide an additional layer of fault tolerance.
Geographically dispersed clusters are also referred to as stretched clusters.
The following rules must be followed with geographically dispersed clusters:
• A VLAN connection with latency of 500 milliseconds or less ensures that cluster consistency can
be maintained. If the VLAN latency is over 500 milliseconds, the cluster consistency cannot
be easily maintained.
• All nodes must be on the same subnet.
Cluster groups and resources, including fi le shares
Management tasks for a cluster include creating and managing cluster resources and cluster groups. The
Cluster Administrator tool provides complete online help for all cluster administration activities. Cluster
resources are created and then assigned to logical, organizational groups. Ownership of these groups
should be assigned in a balanced arrangement between the server nodes, distributing the processing
load between the two nodes.
Cluster resources include administrative types of resources as well as
fi le shares. The following paragraphs
include overview and planning issues for cluster groups, cluster resources, and clustered fi le shares.
Creating and managing these resources and groups must be managed through Cluster Administrator.
Complete online help for creating the various cluster objects is available in the Cluster Administrator tool.
Cluster group overview
A default cluster group is automatically created when the cluster is fi rst created. This default cluster group
contains an Internet Protocol (IP) Address resource, a Network Name resource, and the Quorum disk
resource. When the new cluster is created, the (IP) address and the cluster name that were speci fi ed
during setup are set up as the IP address and network name of this default cluster group.
CAUTION:
Do not delete or rename the Cluster Group or IP Address. Doing so results in losing the cluster and
requires reinstallation of the cluster.
When creating groups, the administrator’s fi rst priority is to gain an understanding of how to manage the
groups and their resources. Administrators may choose to create a resource group and a virtual server
(IP Address resource and Network Name resource) for each node that will contain all resources owned
by that node, or the administrator may choose to create a resource group and virtual server for each
physical disk resource. Additionally, the administrator should try to balance the load of the groups and
their resources on the cluster between the two nodes.
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Cluster administration