ReadyNas Encryption Key Creation?

hopefully someone has seen or read somewhere how the encryption key that is stored on the usb stick is created. i attempted a search on this site and looked in the manuals, found very little, if any info about this.

It is great that AES-256 bit encryption is used on the volume to encrypt all the data (very secure). but what i have yet to find is how the encrytion key is created that is used by the AES-256 encryption scheme. when i created my encrypted volume, the key was insantly created and written to my usb stick, this seemed a little to fast, so does any one know....

what is used for variables to create the key? clock? volume name? array name? type of drives/model number? etc?

where is the random number generator (entropy), or what random number generator routine module is being used, if any?

the key file is 2,732 bytes in size, if the AES-256 encryption routine uses a 256-bit key (32 bytes), what is all this other data?  is this key file an actual key or more likely a SHA Hash, en_DEK (encrypted encryption key) or KEK (key encrytion key) of some sort?

thank you for any information or possible resource that can be read/pointed too.

j