Method, apparatus and computer program product for managing cache

An apparatus for managing a cache, comprising:

• at least one processing unit;
• at least one memory, the at least one memory being coupled to the at least one processing unit and has instructions stored thereon and executed by the at least one processing unit, the instructions, when executed by the at least one processing unit, causing the device to perform acts, the acts comprising:
• creating a primary cache in a storage system;
• in response to the primary cache being created, sending a first request to a hardware management module in the storage system to obtain first information about a first virtual disk in the storage system,
• wherein the storage system comprises at least one physical disk having a plurality of extents, the plurality of extents comprise a first group of extents for creating a first disk array, and the first virtual disk is created by the hardware management module based on at least one spare extent from the first group of extents, the at least one spare extent from the first group of extents being reserved for rebuilding the first disk array;
• in response to receiving the first information from the hardware management module, creating a secondary cache using the first virtual disk;
• and
• in response to an available capacity of the primary cache being below a predetermined threshold, flushing at least one cache page in the primary cache to the secondary cache.

A computer program product having a non-transitory computer readable medium which stores a set of instructions to manage a cache;

• the set of instructions, when carried out by computerized circuitry, causing the computerized circuitry to perform a method of:
• creating a primary cache by a cache management module in a storage system;
• in response to the primary cache being created, sending a first request to a hardware management module in the storage system to obtain first information about a first virtual disk in the storage system,
• wherein the storage system comprises at least one physical disk having a plurality of extents, the plurality of extents comprise a first group of extents for creating a first disk array, and the first virtual disk is created by the hardware management module based on at least one spare extent from the first group of extents, the at least one spare extent from the first group of extents being reserved for rebuilding the first disk array;
• in response to receiving the first information from the hardware management module, creating a secondary cache using the first virtual disk;
• and
• in response to an available capacity of the primary cache being below a predetermined threshold, flushing at least one cache page in the primary cache to the secondary cache.