Tiering adjustment upon unmapping memory in multi-tiered systems

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions readable and/or executable by one or more processors to cause the one or more processors to perform a method comprising:

• receiving, by the one or more processors, 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, each storage tier comprising a plurality of hardware-based data storage devices;
• sending, by the one or more processors, an instruction to unmap the first logical extent from the higher storage tier;
• sending, by the one or more processors, 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, by the one or more processors, an instruction to remove the unmapped first logical extent from the higher storage tier;
• selecting, by the one or more processors, at least one second logical extent located in the lower storage tier for promotion to the higher storage tier, wherein the at least one second logical extent is selected using a heat map;
• and
• sending, by the one or more processors, an instruction to relocate the at least one second logical extent from the lower storage tier to the higher storage tier.

A system, comprising:

• one or more processors;
• and
• logic integrated with the one or more processors, executable by the one or more processors, or integrated with and executable by the one or more processors, the logic being configured to:
• receive, by the one or more processors, 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, each storage tier comprising a plurality of hardware-based data storage devices;
• send, by the one or more processors, an instruction to unmap the first logical extent from the higher storage tier;
• send, by the one or more processors, 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;
• send, by the one or more processors, an instruction to remove the unmapped first logical extent from the higher storage tier;
• select, by the one or more processors, at least one second logical extent located in the lower storage tier for promotion to the higher storage tier, wherein the at least one second logical extent is selected using a heat map;
• and
• send, by the one or more processors, an instruction to relocate the at least one second logical extent from the lower storage tier to the higher storage tier.