A memory device may include logical units configured to store data, wherein the logical units are identified by corresponding logical unit numbers (LUNs) and are associated with corresponding LUN queue groups. Each LUN queue group may include LUN queues that are each associated with a respective intra-LUN priority level that indicates a priority of a LUN queue within a LUN queue group. The LUN queues are each associated with a respective execution priority level that indicates a priority for execution of commands in a LUN queue across LUN queue groups. A quantity of intra-LUN priority levels may be greater than a quantity of execution priority levels. A LUN scheduler may be configured to select and transfer commands from LUN queue groups to the execution queue group based on intra-LUN priority levels. A command executor may be configured to execute commands from the execution queue group based on execution priority levels.