HP Surestore NAS 8000 SAN Solution Integration Manual

8 Network and Storage Planning
Basic Storage Configuration
The most basic storage configuration consists of one LUN and one Volume Group. This
configuration provides access to the full amount of available disk space and allows you to
subdivide the entire capacity into multiple file volumes and snapshots. While this is the most
flexible setup for a system with all physical storage on a single array, using a single volume
group limits options for future system upgrades.
With SAN configurations, physical storage normally resides on multiple storage devices within
the SAN. LUNs are created using the array’s management software. To ensure that a volume
group does not become unavailable due to hardware problems on a specific storage device,
the safest configuration is to create a separate volume group for each LUN.
Note When a volume group includes LUNs from multiple arrays, if any one array has
a hardware failure, the entire volume group will be unavailable. By creating a
separate volume group for each LUN, you are ensuring that only that portion of
the storage residing on the failed array will be unavailable until the array is
restored. All other storage will remain unaffected.
You should choose a single volume group configuration only when both of the following are
true:
■
You have created only one LUN, or you are certain that all LUNs are on the same physical
storage device.
■
You do not intend to upgrade to a high-availability configuration at any time in the future.
Figure 1 Single Volume Group Configuration