International Business Machines Corporation
Tiering adjustment upon unmapping memory in multi-tiered systems

Abstract:

A computer-implemented method, according to one embodiment, includes: receiving an unmap command, the unmap command identifying a first logical extent located in a higher storage tier of a multi-tiered data storage system having the higher storage tier and a lower storage tier, sending an instruction to unmap the first logical extent from the higher storage tier, sending an instruction to decrement a heat associated with the unmapped first logical extent in response to sending the instruction to unmap the first logical extent, sending an instruction to remove the unmapped first logical extent from the higher storage tier, selecting, using a heat map, at least one second logical extent located in the lower storage tier for promotion to the higher storage tier, and sending an instruction to relocate the at least one second logical extent from the lower storage tier to the higher storage tier.