Controller and method for virtual LUN assignment for improved memory bank mapping

A method for creating a metablock across multi-chip memory packages, the method comprising:

• performing in a controller comprising one or more interfaces through which to communicate with a plurality of multi-chip memory packages, wherein each multi-chip memory package comprises a plurality of memory dies, and wherein each memory die has a respective plurality of memory blocks, some of which are good blocks and some of which are bad blocks:
• determine a number of good blocks in each memory die in each of the multi-chip memory packages;
• based on the determined number of good blocks in each memory die, select a memory die from each of the multi-chip memory packages to access in parallel, wherein the selected memory dies are not necessarily all in the same relative position in each multi-chip package;
• and
• create a metablock from a set of good blocks from each of the selected memory dies, wherein a maximum number of metablocks that can be created across the selected memory dies is determined by a lowest number of good blocks in the selected memory dies.