I'm in the process of designing a cluster and would like to get as much capacity (using SSDs) that I can squeeze out of my budget. I've been reading documentation and various posts regarding the changes to multiple data paths as well as the benefits to RAID 0.
I don't like the idea of a single drive failure in a RAID 0 bringing down the entire node because I'm looking at ~20TB worth of data, but I'm not sure if I need the performance gains of RAID 0. What I'd like to do is create multiple smaller RAID 0 groups and then use multiple data paths to stripe across.
So I have a few questions:
If I match my shard count to the number RAID volumes, will ES store one shard per volume per index? For example, if I have 6 RAID 0 volumes and I specify 6 shards, for a single index, will that result in each RAID volume containing 1 shard of that index?
In the event of disk failure, ES should become angry. My plan is to monitor the logs for a disk failure, recreate the volume, and mount it back to the original location. When ES resumes, will it replicate the exact same shards that were on the failed volume back to the new volume?
Should I even use RAID 0 in this situation? Would having 25 disks mounted separately be a safer bet if I don't need the performance gains of RAID 0?
I look forward to testing this all myself, but I'm wondering if I've missed anything before I start the proof of concept.
Thanks for your help!