Policy for storing data objects in a multi-tier storage system

A computer system comprising:

• a processor;
• and
• memory coupled to said processor and having stored therein instructions that, if executed by said computer system, cause said computer system to execute a method comprising:
• accessing data associated with a data object, wherein the amount of said data changes from a first amount at a first time to a second amount at a second time;
• at said first time, storing a first portion of said first amount of data in a first tier of a multi-tier storage system, said first portion corresponding in size to a first specified percentage of said first amount of data, wherein said first portion is selected according to information associated with said data, and wherein the remaining portion of said first amount of data is stored in one or more other tiers of said multi-tier storage system;
• and
• at said second time, allocating said second amount of data between said first tier and said one or more other tiers as necessary so that a second portion of said second amount of data is stored in said first tier, said second portion corresponding in size to a second specified percentage of said second amount of data, said second portion selected according to said information.

A computer-implemented method comprising:

• determining the size of a data object at a first time;
• at said first time, storing a first portion of said data object in a first tier of a multi-tier storage system, said first portion corresponding to a first specified percentage of the size of said data object at said first time, wherein said first portion is selected according to information associated with said data object, and wherein the remaining portion of said data object at said first time is stored in one or more other tiers of said multi-tier storage system;
• determining the size of said data object at a second time;
• and
• at said second time, allocating said data object between said first tier and said one or more other tiers as necessary so that a second portion of said data object at said second time is stored in said first tier, said second portion corresponding to a second specified percentage of the size of said data object at said second time, said second portion selected according to said information.