This book provides comprehensive instructions for setting up and operating a Samba4 environment. One focus is on using Samba4 as an Active Directory domain controller. All steps required for administration are described, right through to troubleshooting domain controller failures. Another focus is on administering file servers in a network environment, either as individual servers or as a cluster. The cluster is set up using only opensource software. GlusterFS is used as the cluster file system. The integration of Windows, Linux, and macOS clients is also covered in detail. Other topics covered in the book: - Setting up two DHCP servers for a fail-safe DDNS environment is described with all steps and scripts. - CTDB is extended to provide high availability for NFS servers. - Administration via the command line and scripts. - The topic of security is also examined in more detail. - Setting up a Samba environment with Ansible. - Migrating an existing domain. - Disaster recovery of an Active Directory domain. - Samba as a print server. - Troubleshooting help. All of the points listed here deal with techniques and the possibilities they offer. All topics covered here are explained using easy-to-follow examples.