[Guest]

I tried a DROBO; it kept failing (not the discs but the electronics in the enclosure) so I gave it up as a bad joke. I may just have been unlucky, but there seem to be reports of others...

 

I now use two four drive 8TB RAID enclosures at different sites, each formatted as 4TB RAID1

 

The most cost effective solution is to buy a 4 enclosure bay, and look around for a good price for four 2TB drives to put in it...

 

Or of course LaCie and others will sell you the box ready to go.