Span drives

I have four 4TB WD drives, I would like to span them so that I have two 8TB drives.  Can this be done, and if so … how?  I plan to use the first span for all my files and the second as a backup.

Hi pecck1, yes it is possible, check page 67 of the manual for more information. 

http://www.wdc.com/wdproducts/library/UM/ENG/4779-705113.pdf#page=72

I taken a look and it doesn’t go into much depth with spanning.

When I click on the “change raid mode” and select “spanning” I’m only given the option of having “Volume_1” with 15,984GB.  What I want is to have “Volume_1” and “Volume_2”, each with 8TB.  I’m trying to stay away from RAID as all my drives are the “black” series and they aren’t that great for RAID.