I've been reading all over the wiki and forums for my first unraid server and I'm assembling my parts for a build right now. I wanted to clear up my understanding regarding the parity drive and what makes the most sense for my setup.

 

The Parity drive must be the largest or equal to the largest disk in the system. These are the drives I have in my hands:

 

1x 2TB WD Green

1x 1TB Hitachi 7200rpm

2 x 500GB WD Blue 7200rpm

 

 

I would like to add a new green hard drive to my setup - would it make sense to add a 3TB or 2TB drive? If I add a 3TB drive, that would become my parity drive, so in essense either adding a 3TB or 2TB drive, I would get the same increase in storage space. To me it sounds like I would be "losing" 1 TB of space if I added a 3TB drive.

 

What makes the most sense in my situation? Eventually I will be replacing the 500GB drives as well. TIA

 

 

Well, if you ever want to use 3TB drives in the future, you'll have to have at least one. So it makes sense to get a 3TB now so you can add more to the array in the future.

I just replaced a 2TB parity that was still good with a 3TB parity in my system that only has 1 and 2 TB data drives in it now. I did this because if I ever need to replace a data drive I will want to replace with a 3 TB drive and if I didn't already have a 3TB parity I would be looking at buying 2 new drives at once.

 

Since my old parity was still good I then replaced one of my 1TB data drives with my old 2TB parity drive so I increased my data capacity by 1TB anyway. This whole process took several days as you can imagine.