Systems and methods disclosed herein allow for efficiently managing unmapped blocks to extend life of solid-state drives. In one aspect, a method includes: determining a quantity of unmapped storage units in the storage device and operating the storage device in a first mode of operation while the quantity satisfies a first threshold. The method also includes: changing to a second mode of operation if the quantity of unmapped storage units doesn't satisfy the first threshold. While operating in the second mode of operation, the method includes: determining whether processing a write command would reduce the quantity of unmapped storage units to a quantity less than a second threshold. If processing the write command wouldn't reduce the quantity of unmapped storage units to a quantity less than the second threshold, the method includes: accepting and processing the write command. Else, the method includes: forgoing acceptance and processing of the write command.