HP Surestore NAS 8000 High Availability Solution Integration Manual

10 Network and Storage Planning
HA Storage Configuration
This section provides suggestions for configuring the storage on a NAS 8000 with
high availability features.
On a simple direct-attach NAS system without HA features, the simplest way to configure the
storage is to create a single LUN for the entire array and create one volume group with multiple
file volumes beneath it. However, in an HA cluster with two NAS Servers, each volume group
can be active on only one NAS server, or
node , at a time. Therefore, if you are using active/
active failover packages (see “Failover Packages” on page 8), you must create at least two
volume groups so each node can access some of your storage.
When determining how many LUNs and volume groups to create, consider the following:
■
A volume group can be active on only one node at a time.
■
A volume group can be assigned to only one failover package.
■
File volumes can’t be split between packages or nodes.
■
Multiple volume groups can be assigned to the same package.
■
A package can only run on one node at a time.
■
The HA cluster is limited to 30 packages total (both nodes combined).
■
A package is the smallest unit of failover.
■
A volume group is the smallest unit of storage that can be failed over.
■
If a package contains multiple volume groups and a single volume group, file volume or
even share fails, the entire package will be failed over.
■
More packages means a higher degree of granularity to balance the packages between the
nodes and detect failures.
■
More packages also results in higher complexity in the cluster configuration and requires
more virtual IP addresses to keep track of.
■
The packages should be divided between the cluster nodes such that the storage access
load (from client systems) will be balanced. This may or may not correspond to balanced
storage capacity between the nodes.
The illustrations on the following pages depict three common storage configurations:
■
Single array with one LUN and one Volume Group for active/passive failover
configurations.
■
Single array with multiple LUNs, volume groups and packages.
■
Multiple arrays, LUNs, volume groups and packages.