Hierarchical address virtualization within a memory controller and configurable block device allocation are disclosed. Respective virtual block devices (VBDs) are defined in flash memory managed by a common memory controller, with data access managed using address virtualization techniques. The common memory controller then tracks the need for maintenance operations independently for each VBD. Information may be received from the common memory controller regarding the need for maintenance operations in respective virtual block devices (VBDs), and commands are then selectively issued to the common memory controller in a manner so as to independently schedule these operations for the respective VBDs; performance of maintenance operations by the memory controller in a first VBD is unconstrained by performance characteristics associated with a second VBD.