Enabling virtual nodes on a new cluster 

Steps and recommendations for enabling virtual nodes (vnodes) on a new cluster.

Generally when all nodes have equal hardware capability, they should have the same number of virtual nodes (vnodes). If the hardware capabilities vary among the nodes in your cluster, assign a proportional number of vnodes to the larger machines. For example, you could designate your older machines to use 128 vnodes and your new machines (that are twice as powerful) with 256 vnodes.

The location of the cassandra.yaml file depends on the type of installation:
DataStax Enterprise 5.0 Installer-Services and package installations /etc/dse/cassandra/cassandra.yaml
DataStax Enterprise 5.0 Installer-No Services and tarball installations install_location/resources/cassandra/conf/cassandra.yaml
Cassandra package installations /etc/cassandra/cassandra.yaml
Cassandra tarball installations install_location/resources/cassandra/conf/cassandra.yaml

Procedure

Set the number of tokens on each node in your cluster with the num_tokens parameter in the cassandra.yaml file.