froggit Wrote:So:
- you hate the idea of spending money on spinning disks up
- you hate the idea of spending money on buying one extra disk*
I think you are misconstruing things here. It is not always about straight costs of power and disks.
On the first point, I personally don't care about the power costs of spinning disks up. Here in Texas my power comes from Wind Turbines so I can waste as much as I want and all it hurts is my wallet, not mother nature.
But I am scared that running consumer drives ALL THE TIME wear them out based on my experience with my RAID 5 server, and I think the only way you can get four years out of consumer drives is to spin them down whenever you can.
There is a cost component there because I could easily just buy enterprise drives made for RAID (and therefore ZFS) instead, but personally the idea of spending twice as much on storage as I could seems like a poor deal when I can just use different software that leaves the drives spun down most of the time.
On the second point, buying an extra disk is no big deal. Heck I have a extra 2TB drive on my desk that isn't in my Unraid server yet because I don't need the space yet.
The real problem is that the extra disk takes an extra slot that I could use for storage. My larger server can only take 16 disks as is, and the second I go past 16 disks I need to spend serious money upgrading to a 20 bay Norco. And once you get enough data to fill those drives, the next option is to rebuy EVERYTHING (mobo/case/PSU/etc.) to buy another server.
The real costs that hurt is not the per drive cost, it is the per bay cost. Drives are outright cheap when compared to all the hardware it takes to make that drive work.
Therefore I want as many available bays as possible working towards storage, as that means I can go that much longer before I need to build another server and spend some real money.
The idea of tying up two or three bays with parity drives when I could just use one seems wasteful, especially because this isn't some server that is gonna get me fired if some data gets lost (I just lose some free time to re-rip/download).
The main reason why RAID servers have more than one drive fail at once is because:
-The usage of the server is so intense that when another drive dies the rest are super stressed till it is replaced because the server can't have downtime
Or
-Because RAID/ZFS requires all the drives to be the same make and size for optimal results you often buy the drives at one out of single batch that could have issues
With Unraid I avoid the second scenario by mixing and matching drive sizes and brands. In my big server no two drives are the same.
I avoid the first scenario by taking my server offline when a drive dies, and I let it rebuild the lost disk without any other pressure. I tell the wife that "tonight we can't watch XBMC because my server needs repairs, lets go see a movie in the theater instead" and I let Unraid do its rebuild thing in a low stress environment.
Now obviously I couldn't do this at work where that server must be online for business to happen, but that is why home use can have differing solutions.
No one solution is better than another completely, and there is no "obvious answer" for a mediaserver. If you value you time more than anything and you are only ripping stuff you legitimately own, than maybe ZFS with tripple redundancy is perfect. If you value hoarding as much illicit content off the usenet as possible before it gets past the retention mark and every byte you can free for storage seriously helps with the quest, then Unraid with its one drive parity makes sense.
Each to their own, and each technology for whatever needs fit it best!