HP StorageWorks 8000, Руководство пользователя

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HP NAS 8000 Concepts
34 HP StorageWorks NAS 8000 User’s Guide
Failover Packages
In order to implement a shared-nothing resource model, the storage must be
divided up into separate, stand alone units that can be served by all the nodes in
the cluster and that can move from one node to another. These units of storage and
their associated resources are called failover packages. Failover packages are the
smallest unit of failover within the cluster.
In addition to the storage that each failover package controls, there is a special IP
address (referred to as a virtual IP address) through which all access to the storage
is provided. A virtual IP address is the same as any other IP address, except it
must not be the same as any cluster node or any other computer in the network.
Clients must use the package’s virtual IP address, rather than the node’s IP
address, when accessing the storage. That way, clients need not know or care
which actual node in the cluster is providing access to the storage using the virtual
IP address. The VIP virtual IP address floats with the failover package to whatever
node is running it.
Each cluster can have a maximum of 30 packages running concurrently. For NAS,
the failover package defines the volumes (file systems) and their associated CIFS
shares and NFS exports that should be failed over. A given volume group can be
defined in only one failover package at a time, but a failover package can contain
multiple volume group definitions. The packages can fail over automatically when
a server fails, or they can be manually failed over one at a time. A given failover
package can be running on only one cluster node at a time.
Think of a failover package as a group of one or more volume groups (with their
file systems, shares/exports, and virtual IP address) that will fail over as a single
unit. To fail over a package manually, you must:
■
Stop the existing failover package (in the case of a service, network, or
resource failure).
■
Start the new instance of the failover package on a different node. You can
manage failover packages on the Storage tab of Command View NAS.