To multi or hardware RAID or not?

(None) #1

So I have my servers with RAID 0 over 6 drives. We lost a disk, no sweat we had replicas in the cluster.

Just thinking should I try setting up using multiple paths?

Thinking of creating 3 RAID 0 drives and then setting up ELasticsearch to use those 3 paths.

Is that a good idea? If we had done this earlier. We would have only lost that 1 RAID only those shards correct, bit not the whole 6 disks?

(None) #2

Ok so I went down this route...

I created 3 separate logical disks using RAID0 from the 6 disks. And I configured ES to have 3 data paths. Seems to be working Ok so far.

(Jason Tedor) #3

It depends. :slight_smile:

The tradeoffs are pretty straightforward. Multiple paths in stripes your shards across the paths (at the shard level), and using RAID 0 stripes your shards across the disks (at the block level). In the first case if you lose a disk, you lose the shards on that disk and nothing else. In the second case, if you lose a disk, you lose all of your shards on that machine. Therefore the first gives you increased safety, but the trade off is lower performance.

It depends on your workload whether or not you need the increased performance, and whether or not you have the risk appetite to accept the reduced safety that comes from choosing the increased performance.

(None) #4

Yeah that's fine. Testing with a hybrid approach.

(system) #5