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Are multiple used smaller drives really more cost effective than fewer new larger drives once you take into account cost of power, HBA, backplane and lifetime o

Are multiple used smaller drives really more cost effective than fewer new larger drives once you take into account cost of power, HBA, backplane and lifetime of used drives? I'm a data hoarder too (proof): https://i.imgur.com/j9jk9OP.jpg https://i.imgur.com/j9jk9OP.jpg But always been curious about cost so let's do some sums... With a used 3TB setup. Assume 12x3TB = 36TB storage. A reasonable 2U server would be needed to support that which would include a backplane and HBA. Power consumtpion would be 12x 5W (HD) + 10W (HBA) + 65W (server). Total is 135W. Power cost in UK for one year at 24/7 is approx £176. Assuming used 3TB drives give us two years of reliable operation and cost £30 each to buy (going price on ebay a few months back) total cost to buy would be £360 of just the drives (not including the server). Add cost of electricity for two years operation and we get a total of £712. Average the cost per year (£712/2) and we come to £356 per annum for the 3TB drive setup. Now with new 12TB drives. 3x12TB consumes 3x 5W of power + 30W for the server (no backplane or HBA needed). Total is 45W. Power cost in UK for one year at 24/7 is approx £60. Cost of drives would be 3x£300 = £900. Assume we get 5 years of life out of these new drives, plus electricity costs of £60 - over 5 years total would be £1200. Averaged the cost per year (£1200/5) and we come to £240 per annum for the 12TB drive setup. (I have not counted the additional cost of the 2U server for the 3TB scenario since that would complicate the math since servers tend to last longer than drives.) So I'm wondering what the appeal of large servers with lots of small drives is when back of the envelope math suggests it costs more in the long run. Unless of course it's because you like those blinkin' lights :) https://i.imgur.com/4ypumBQ.jpg https://i.imgur.com/4ypumBQ.jpg

sokoloff 6y ago
What level of redundancy are you calculating? I’m not comfortable with less than RAID6/Z2 on large drive arrays, so 3 12TBs is only 12TB usable. 12 3s I’d probably do 2 6-drive volumes, each with 2 drive redundancy, so 2x4x3 or 24 TB usable. That’s enough to flip the math.
m463 6y ago
The calculations might depend on whether the drives are powered on all the time.
- omgwtfbyobbq 6y ago
  That's my sense too. Unless someone has to have access to that data relatively quickly all the time I don't see why the system couldn't be left off. Even if the data is accessed frequently, lets say once every day or few, it could still be left off most of the time if someone is OK with waiting a few minutes for everything to power up.
stock_toaster 6y ago
> Are multiple used smaller drives really more cost effective than fewer new larger drives once you take into account cost of power, HBA, backplane and lifetime of used drives? Resilver times for drive replacement is generally much faster for smaller drives.
sneak 6y ago
Oh, I got one of them to be a disk duplication machine for the next Defcon. Only one of them will be in full file server service, and I intend to do an 8-20 disk array of 12TB disks. That will still leave me with over a dozen slots for a secondary array of cheap refurb disks of any kind I can come across. Power is cheap here; my current hobby bottleneck is drive cost. Ideally I’d be able to buy a few dozen extremely cheap disks that have been pulled from service that someone wants to dump as a lot.

sokoloff 6y ago

What level of redundancy are you calculating? I’m not comfortable with less than RAID6/Z2 on large drive arrays, so 3 12TBs is only 12TB usable. 12 3s I’d probably do 2 6-drive volumes, each with 2 drive redundancy, so 2x4x3 or 24 TB usable. That’s enough to flip the math.

m463 6y ago

The calculations might depend on whether the drives are powered on all the time.

omgwtfbyobbq 6y ago
That's my sense too. Unless someone has to have access to that data relatively quickly all the time I don't see why the system couldn't be left off. Even if the data is accessed frequently, lets say once every day or few, it could still be left off most of the time if someone is OK with waiting a few minutes for everything to power up.

stock_toaster 6y ago

> Are multiple used smaller drives really more cost effective than fewer new larger drives once you take into account cost of power, HBA, backplane and lifetime of used drives? Resilver times for drive replacement is generally much faster for smaller drives.

sneak 6y ago

Oh, I got one of them to be a disk duplication machine for the next Defcon. Only one of them will be in full file server service, and I intend to do an 8-20 disk array of 12TB disks. That will still leave me with over a dozen slots for a secondary array of cheap refurb disks of any kind I can come across. Power is cheap here; my current hobby bottleneck is drive cost. Ideally I’d be able to buy a few dozen extremely cheap disks that have been pulled from service that someone wants to dump as a lot.