Abstract: In the hierarchical storage management (HSM)，it is difficult to choose a data migration policy which meets precisely the diverse and the changes in business data access patterns, so that the concept of policy priority could help to quickly choose the most appropriate policy for the HSM system. The value of a policy priority is dynamically adjusted before and after a migration which is driven by the policy, and then, the HSM system chooses the policy that has highest priority value as the policy for the next migration. After a few adjustments like this, the system will obtain the optimal policy. The prototype experiments show that the method can indeed adaptively choose the best policy by dynamically adjusting the priority, therefore, the impact on the business applications is greatly reduced.

Key words: HSM, Migration policy, Priority, Adaptively choose