Managing a cache memory

A method of managing cache memory, comprising:

• using a first cache memory;
• copying data from the first cache memory to a second cache memory;
• providing data from a disk storage area to the first cache memory;
• providing data from the disk storage area to the second cache memory, wherein the first and second cache memories contain at least some data that is different;
• writing a portion of the data to both of the cache memories in response to the portion of data being modified while stored in the cache memories;
• subdividing the first cache memory into primary and secondary storage areas;
• subdividing the second cache memory into primary and secondary storage areas, wherein primary areas of the first cache memory correspond to secondary areas of the second cache memory and wherein secondary areas of the first cache memory correspond to primary areas of the second cache memory;
• and
• providing data from the disk storage area to the one of the cache memories having a corresponding primary storage area.

A method of managing cache memory, comprising:

• using a first cache memory;
• copying data from the first cache memory to a second cache memory;
• providing first and second physical cache areas;
• subdividing each of the first and second physical cache areas into first and second logical cache areas, wherein portions of the first logical cache area are provided on both the first and second physical cache areas and portions of the second logical cache area are provided on both the first and second physical cache areas;
• assigning portions of data from a disk storage area to one of:
• the first logical cache area and the second logical cache area;
• and
• providing data from the disk storage are to one of the physical cache areas according to assignment of the data to a particular one of the logical cache areas.