Western Digital WD RED WD40EFRX with ReadyNAS Duo V2 not giving more than 3.6 TB

[4JamesKirk]

Hello I have 2 Western Digital WD RED WD40EFRX In my  ReadyNAS Duo V2 and it is acutally the V2 I have checked with Firmware version 5.3.13 and both drives show up but the max I can get it to format to is 3.6 TB no matter which version of RAID I choose 0 or 1.  both of which are odd.  Can anyone help me out to get past 3.6 TB?  Thank you!

[StephenB]

The safest option to maximize space is to choose JBOD (one 3.6 tb volume for each disk), and then put some shares on each volume.