I have a packaged deployment of DataStax Enterprise on Ubuntu. I got the DSE service up to make sure everything works. Then I shut the service down because I wanted the data to go on a different directory: /mnt/datadrive/lib/cassandra
I updated the /etc/dse/cassandra/cassandra.yaml file in the following locations:
data_file_directories:
- /mnt/datadrive/lib/cassandra/data
commitlog_directory: /mnt/datadrive/lib/cassandra/commitlog
saved_caches_directory: /mnt/datadrive/lib/cassandra/saved_caches
Basically, wherever there was a reference to the /var/lib/cassandra folder, I changed to /mnt/datadrive/lib/cassandra.
After staring up the service, I checked the status with sudo service dse status, and I found that the dse daemon wasn't running.
I'm assuming that all of the data files are created in the appropriate directories when the service starts up, since I've blown out the /var/lib/cassandra folder and restarted the service just to make sure. However, when I changed the data directory, the service won't start up. There must be more places than cassandra.yaml that reference the data directory.