My case/system can hold 11 drives. Every six months or so I upgrade the smallest to a larger disk but I'm only gaining a few TB this way if I replace a 2 for a 4-6TB so it almost seems better to build a new system.  My unraid box is almost six years old too so there is better tech out there now and I've learned a few things not to do again. I know energy wise this is not the best solution and probably cost too but it does have the benefit of giving me more storage and possible backup solutions if I move the second box to a different location. Have people done this, confused as to what solution to try.

What's your mix of 2TB vs. 4/6TB drives now?

What's your mix of 2TB vs. 4/6TB drives now?

 

6TB parity - 5TB-3, 3TB-4, 2TB-3

Well, a couple of thoughts.

 

A new server would be more energy efficient.  But it would be years (decades, actually) before the energy based cost savings added up to anything substantial.  A new server could have a faster CPU and more memory - but you don't mention any trouble there.

 

Lastly you could have more disks or bigger disks in a new server.  You have 33TB of storage today.  Using 8TB disks you could almost fit that on 3 disks!  (Plus another for parity).  That's the main reason I'd build a new server if I were you - but you'd need to be prepared to buy the bigger disks which are expensive.  I'd keep the existing server to serve as a backup for critical files, and if you have a friend or relative who'd be willing to host it then you have a real backup solution.

6TB parity - 5TB-3, 3TB-4, 2TB-3

 

A few thoughts ...

 

(a)  You've already "bit the bullet" r.e. the cost of fault-tolerance by buying a 6TB parity drive.  That's the one drive you have to buy that adds ZERO storage capacity.

 

(b)  Your 5TB drives are so close to the max size (6TB) that I wouldn't even consider upgrading those ... just wait for them to fail and then replace them with a 6TB drive if/when that happens.

 

©  Replacing the 2TB drives with 6TB drives is a reasonable approach for adding capacity => the cost/TB will be 50% higher than if you simply ADDING a 6TB drive ... but there's no additional infrastructure cost (i.e. another system) ... AND you'll gain a few 2TB drives for storing backups or otherwise re-purposing them.  Of, if you do this while they're still error free and don't have an excessive number of hours shown in the SMART data, you can sell them on e-bay and reduce the effective cost of the upgrade.  A check of completed (sold) e-bay listings shows that 2TB WD drives with clean SMART data (no reallocated or pending sectors) have recently sold for between $42 and $70.

 

(d)  Replacing the 3TB drives with 6TB drives would double the cost/TB compared to simply adding a 6TB drive; but as with the 2TB units, you could likely recoup a good bit of that by selling them on e-bay IF you do it whlie they're still "clean."    These have recently sold on e-bay for $55 to as much as $88 (for a 3TB Red).

 

What you might want to do is get SMART reports from all your 2TB and 3TB drives; and, one-at-a-time, list the "clean" drive on e-bay at a minimum bid price you'd be happy with => and if they sell, simply replace them with 6TB drives as you sell them.    If you do this, you should buy a 6TB drive BEFORE you list the first drive; so if it sells you can immediately remove it from your system and ship it to the buyer.    Then just buy another 6TB drive and repeat the process 

 

On the other hand, if you want to make a significant jump in capacity AND upgrade to dual parity, you may want to buy "bite the bullet" for a new system with 8TB drives.    But this would involve buying new hardware;  2 8TB drives for parity; and THEN you'd start actually gaining storage as you bought additional 8TB drives.  At the current price of 8TB Reds ($322), that's $644 for the parity drives, plus the cost of a new system ... i.e. well over $1000 before you starting buying data drives.    But it WOULD give you a much-higher capacity system in the end.

 

If you don't have backups; this approach makes sense; but otherwise you're probably better off just updating your current system until it at least nears its max capacity.