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I'm building multiple storage nodes for Riak database. Each node contains 20-40 x 2TB drives. Riak replicates each save to 3 nodes so there I have redundancy. Now the question is that what's the best and most efficient way to create one "virtual harddrive" per node without actually risking losing data if drive collapses (RAID 0) or doing unnecessary replication (RAID 1+)? I'm using Ubuntu Server.

Originally I was thinking about using ZFS but I'm open for suggestions.

James
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I would struggle to suggest any file system other than ZFS for any purpose. Unless your using it under linux, then i'd timidly suggest you use LVM

SuperBOB
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Well if you have redundancy across three nodes you should be able to use RAID 0 surely? That way if a disk fails you can rebuild the node once you have a new disk in place and copy the data from another node. If you need redundancy at the node level I guess your only option would be RAID 10, or possibly RAID 5 so long as your database isn't too intensive.

Alex Berry
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    The problem with RAID 0 is that if one disk crashes, it takes the whole node with it. That means that in worst case scenario, whole Riak cluster starts rebalancing itself and transfers 100s of TBs around the network. It seems that either I risk huge network spike by using RAID 0 or then I waste A LOT of space just for the sake of avoiding network meltdown. – James Jun 29 '11 at 15:07
  • Hmm... Well what RAID levels do your controllers support? RAID 50 may be an alternative option to save on disk if it's supported, you come close to the performance of RAID 0 but you only "waste" a few disks in the array. The downside of this of course is the performance degradation during a disk failure, and the fact that it's still not as efficient as RAID 0, but still. – Alex Berry Jun 29 '11 at 15:21
  • We still haven't decided on RAID controllers. I haven't played with nested RAIDs before but RAID50 & 60 sure sounds good and might be a solution for this. I'll have to check the prices for controllers that have those levels and see if they fit in the budget. – James Jun 29 '11 at 16:17