10) System and Server Administration

The system administrator, commonly known as SysAdmin, is the guardian of the technological infrastructure and the continuity of corporate IT services. The first rule for efficiently managing servers is to have complete visibility into hardware and software metrics. Accurate analysis of log files (such as syslog in Linux) allows for the identification of anomalous behavior or intrusion attempts. An administrator must rigorously apply the principle of least privilege to protect sensitive data from internal and external risks. In Unix/Linux systems, this translates into careful configuration of file permissions and controlled use of sudo. In a Windows corporate environment, Active Directory is used to centralize authentication through Group Policy (GPO). Keeping operating systems and application software constantly updated is the best way to prevent known security exploits. SysAdmins must carefully plan maintenance windows to avoid sudden interruptions to production services. No system is exempt from failures, making it mandatory to adopt rigorous strategies for saving corporate data. The famous 3-2-1 rule involves keeping 3 copies of data, on 2 different media, with at least 1 copy stored offsite. Automating these procedures through bash, PowerShell, or Ansible scripts reduces human error and guarantees rapid recovery. System administration has moved from manual configuration of individual machines to sophisticated automation guided by code.