Custom policies
The settings of the tiering policy can be changed and these tiering policies changed by a user are called custom policies. Custom policies can be defined for IDs of tiering policies from 6 to 31 (from Level6(6) to Level31(31)). The following items can be set in the custom policy:
- Rename custom policy
- Change allocation threshold
Custom policy name
A custom policy name can be changed arbitrarily. You can change the names of custom policies from Level6(6) to Level31(31). For example, if you change the name of Level6(6) to Policy06, Policy06(6) will then be displayed.
Allocation threshold
You can define allocation thresholds in new policies from Level6(6) to Level31(31).
For all DP-VOLs that have the tiering policy in a pool, Dynamic Tiering performs the relocation of pages to each tier based on the tiering policy setting.
Max(%) and Min(%) parameters: When a tiering policy is created, 4 types of parameters can be set: Tier1 Max and Tier 1 Min, Tier 3 Max and Tier 3 Min. Each parameter setting is a ratio that corresponds to the total capacity of the allocated area of DP-VOLs that have the same tiering policy set for a pool.
Tier1 and Tier3 parameter settings can also limit the capacity for all volumes in a configuration that contain multiple DP-VOLs that have the same intended use. These settings can prevent conditions such as the following from occurring:
- Excess allocation of SSD capacity for unimportant applications.
- Degradation in average response time for high performance operations.