By default, the data tier's log files and CodeStation artifacts are stored in the application data directory. You specified this directory when you installed the server. In the case of high-availability clusters, this directory is in a shared location where each server in the cluster can access it.
Ideally, this data is stored on robust network storage that is regularly synchronized with an off-site disaster recovery facility. In addition, the IBM® UrbanCode™ Deploy server requires a fast network connection to this storage.