Using multi-backend documentation

[JMercerGit]

There is a lack of information about using multi-backend features

[JMercerGit]

@Bob-The-Marauder @pjaclark Can you guys add some context/suggestions for this?

[Bob-The-Marauder]

This would be a more detailed example of how to set up a multi-backend.
For example, have three bitcask backends, one runs expiry after 6 months, another runs expiry after 3 months, the final one doesn't run expiry at all. How do you set that up in riak.conf? How do you set up the buckets to have use the right backend for their type.

As another example, let's say you want to be able to do expiry and 2i, you'll need a Bitcask backend and a leveldb/leveled backend. How do you configure multiple backends in this way and the appropriate buckets?

I plan to tune my hardware so I need different backends on different hard disks to max performance e.g. the regularly accessed stuff on SSD but the large, hardly used archives on magnetic media, how do I do that?