I'm building a new "cluster" (to replace the broken setup I've written about in previous posts) that will consist of only two nodes. I understand that I'll be sacrificing high availability of writes if one of the nodes goes down, and I'm okay with that. I'm more interested in maintaining high consistency and high read availability. So I've decided to use a write-level consistency of ALL and read-level consistency of ONE.
My first question is about the drives in this setup. If I initially set up the system with, say, 4 drives for data and 1 drive for commitlog, and later I decide to add more capacity to the node by adding more drives for data (adding the new data directory entries in cassandra.yaml), will the node balance out the load on the drives, or is it agnostic to usage of drives underlying data directories? My second question has to do with RAID striping. Would it be more useful to stripe the disk with the commitlog or the disks with the data? Of course, with a single striped volume for data directories, it would be more difficult to add capacity to the node later, as I've suggested above. Casey
