Spent some time yesterday building myself a raid 5 backup system. Bought the box, and a couple of new 1tb hard drives, and combined them with 2 existing 1tb hard drives I already had. Got the box all put together and accessible across my wireless network yesterday.
Well this morning I decide to set it up in the Raid 5 configuration ready for using as my new backup solution. Well 5 hours in and its at 26% done. Did some googling and seems formatting and setting up 4 x 1tb drives in a Raid 5 array can take ages, some people have found it takes days to complete.
So just a nice little warning, if you want to setup your own Raid 5, be prepared for it to take quite a while to get to the point where you can actually backup onto it.