Vls Design Considerations; Vls Sizing; Vls9000 Partially Populated Storage Pools - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

across one array. See
storage pool with only one array.
Figure 48 VLS9000 Partially Populated Storage Pools
.
The flexibility of the VLS9000 storage pooling effectively allows the user to partition the disk arrays
to fit the user's environment. For example, if a company has four SANs, each with its own backup
application, the user can configure the storage pools so that there are two arrays per SAN. The
performance of each storage pool is independent and does not impact the performance of the other
pools.
VLS Gateway Storage Pooling
When creating and assigning storage pools, use the following information to ensure even load
balancing:
• Storage pools must be manually configured onto the array LUNs.
• Limit the storage pools to 256 LUNs across the VLS device.
• Keep arrays with the same performance characteristics within separate pools (i.e., place one array
type in one pool and another array type in another pool).
• In configurations with multiple arrays, choose to balance performance so that either the pool
comprises LUNs from every array, or each array is allocated to a separate pool.
• When pooling across multiple LUNs, try to keep the same number of LUNs in each array in the
pool.
• Try to keep approximately the same capacity on each LUN within a storage pool. If LUNs have
different capacities, there may be performance hot-spots when smaller LUNs are filled.
• When presenting LUNs, present only the disks that you wish to use with the VLS12000 because
existing data will be destroyed during storage pool configuration.

VLS Design Considerations

VLS Sizing

Sizing is the art of deciding how much capacity you need and how to best use it. Understanding
capacity requirements requires you to understand the raw capacity of the VLS (in its various models),
the size and nature of your backups, and the retention periods associated with your data.
Outlining the Steps
Here are some basic exercises that can help you understand your capacity needs:
• Identify slow SAN hosts
• Compare the capacity required to hold the data that represents what is backed up from them
Figure 48. If a fourth array is added, the VLS automatically adds it to the
HP StorageWorks VLS and D2D Solutions Guide 123