The SmartTier placement policies support SSD-based tiers with the following features:
Allowance of fine grained temperatures, such as allowing hours as units for the <IOTEMP> and <ACCESSTEMP> criteria
Support of the Prefer attribute for the <IOTEMP> and <ACCESSTEMP> criteria
Provision of a mechanism to relocate based on average I/O activity
Reduction of the intensity and duration of scans to minimize the impact on resources, such as memory, CPU, and I/O bandwidth
Quick identification of cold files
To gain these benefits, you must modify the existing placement policy as per the latest version of the DTD and assign the policy again. However, existing placement policies continue to function as before. You do not need to update the placement policies if you do not use the new features.