Thin Provisioning

Nextra™ offers state-of-the-art “thin provisioning” capabilities: it allows administrators to flexibly define logical volume sizes that are larger than the physical capacity of the system. Unlike traditional approaches to storage, Nextra’s physical capacity just needs to be larger than the actual written data, as opposed to larger than the logical volumes. Physical capacity needs to be increased only when actual written data increases.

Thin provisioning advantages
Using thin provisioning has several advantages:

• Physical capacity can be purchased only when (and if) needed, reducing overall capital expenses and spreading them over a longer period
• Systems are smaller at any given time; they consequently consume less power, generate less heat and need less space
• There is no need to resize a volume, since logical size can be set as the final size from Day One , saving on administration efforts and reducing down-time
• Thin provisioning is "greener," saving energy and supporting environment-conscious objectives

Nextra's thin provisioning advantage
In addition, Nextra offers the unique capability of reclaiming data that was previously in use and is now out of use. This brings several benefits:

• When applications are logically formatting areas of the volume, the formatted capacity will be re-assigned to another volume
• When a volume is migrated from a legacy system, Nextra's thin provisioning mechanism will not allocate any unused space, magically "shrinking" existing volumes upon the migration

Managing thin provisioning
Thin provisioning can also be a potential source of failures, since a sudden change in an application's access patterns can cause the system to run out of available space.

Nextra is tuned toward preventing such scenarios as much as possible. Specifically, Nextra:

• Defines thin provisioning per only specific parts of the system, and defines other parts as non-thin provisioned. This limits the scope of a thin-provisioning problem to a subset of the system.
• Provides detailed reports on usage, enabling the user to assess the situation and order more disk capacity before problems arise.
• Provides alerts via email, SMS or SNMP when usage levels exceed thresholds, giving adequate time to deal with the situation.

For more details, see XIV's thin provisioning white paper.