Can an XRAID-2 with dual redundancy be expanded?

Yes. Then when all drive bays are full you can replace at least four disks with higher capacity disks (one disk at a time of course) to expand it even further.

Thanks,
So just making sure I have this correct. If I have a 4 disk dual redundancy xraid 2 setup then later I buy 2 disks, and i can just put them the unit and it auto expands. I dont have to backup my data and factory reset to increase the array?

Cheers

Yes. If this will make it clearer you may wish to take a look at X-RAID2 dual-redundancy expansion paths, an excellent post by Jedi Knight (do note that this was written before converting from single to dual-redundancy without a factory reset was made possible, so it doesn't allow for that, though this isn't relevant to your situation).

Excelllent thanks. Off to buy the Pro6V2 and 4 x 3TB Hitachi Deathstar disks in the morning ;-)

Great!

Since this is a new setup, I would put one disk in the NAS, update to latest RAIDiator (currently 4.2.17: http://www.readynas.com/RAIDiator_x86_4_2_17_Notes), then power down, put all the disks in and do a factory reset using the boot menu (http://www.readynas.com/kb/faq/boot/how_do_i_use_the_boot_menu), discover the NAS using RAIDar (http://www.readynas.com/downloads) during the 10 minute countdown and select X-RAID2 and check the dual-redundancy option, then confirm your selection. This will give you a clean setup on the latest firmware using X-RAID2 dual-redundancy.

Thanks.
I have the ReadyNas Pro6 Diskless in my hands now, but before I run it up, how can I check it is a Version2?
They said it was but there are no markings on the box re version 2
The part number says RNDP6000-200AJS
Cheers

The -200 indicates that it is a V2.

Ahr thanks, that's the info I was after as I was not sure if any V1's were left in the supply chain etc.
I would like it to be visable somewhere in the admin UI though,
Anyway have flashed the latest FW, sees the 3TB drives and syncing the array now.(5hrs for 12TB.)
Thanks for your help.

In the admin UI, It will say you have a ReadyNAS Pro 6. If you had the V1 it would say ReadyNAS Pro Business Edition.

I think there are some V1s in the supply chain still, but probably not diskless ones.

Enjoy your new NAS.