I found a Document for determining the configurations for the Datastax cassandra nodes. Found here.
http://www.datastax.com/documentation/cassandra/2.0/pdf/cassandra20.pdf
Question
What would be the minimal and the highest setup for a 90TB cassandra cluster. Kindly include the spec of processor, switch, hard disks and RAM. The no. of nodes is 5. Datastax's cassandra is gonna be used, so I guess in-memory function requires more amount of RAM.
Solution
I found a Document for determining the configurations for the Datastax cassandra nodes. Found here.
http://www.datastax.com/documentation/cassandra/2.0/pdf/cassandra20.pdf