I’ve been working with the DataStax Enterprise 2.01 install for a bit now and it was working great until one day I was no longer able to get any queries to work using the cqlsh I was just getting the error that one or more nodes was unavailable. I tried restarting and still nothing would work I got a few errors in the logs (shown below).
I was able to quickly fix the error by removing my data directory and starting fresh as this is just my development environment that works great for me. You can find your data directory in the cassandra.yaml file ($DSE_HOME/resources/cassandra/conf/cassandra.yaml), look for the data_file_directories entry. Mine was set to /var/lib/cassandra/data so I just ran the following and started cassandra fresh and everything is back to working order.