Patent ID: 7496714

Claim:
A method of determining when to destage write data from a fast, non-volatile storage (NVS) of a computer system from an upper level of storage to a lower level of storage in said computer system, said method comprising: adaptively varying a destage rate of said NVS according to a current storage occupancy of said NVS; and adaptively varying a high threshold level in response to a dynamic computer storage workload, in a process comprising: maintaining a desired occupancy level for said NVS; maintaining a maximum occupancy observed varied for said NVS; initializing said high threshold level to be equal to desired occupancy level, wherein said high threshold level is constrained to never exceed said desired occupancy level; if said NVS occupancy drops below a current high threshold level, and if said maximum occupancy observed variable is greater than said desired occupancy level, decrementing and backing-off said high threshold level by a positive difference between said maximum occupancy observed variable and said desired occupancy level; and resetting said maximum occupancy observed variable.