It is possible to take a span that is virtualized by UVM and migrate it to the local storage, using Hitachi Storage Administrator Migrator functionality.
The two principal advantages of migration are:
- A span residing locally is faster than one accessed over UVM (especially if the local storage is newer).
- The server regains the ability to check for free space and protect the HDP pool from running out of space.
If the existing span violates the HDP rules introduced in release 12.1, for example, by spreading a single NAS stripeset across DP-Vols from multiple HDP pools, a migration can bring it into compliance. The best practice is to have one span per thinly provisioned HDP pool.