How to Diagnose and Fix Full Disk Space on a Linux Server

Linux administrators facing full-disk alerts can use a structured set of command-line tools to identify and resolve the issue quickly. The process begins with 'df -h' and 'df -i' to pinpoint which filesystem or inode table is exhausted, followed by 'du' commands to drill down into the largest directories. The 'find' command helps surface oversized individual files such as core dumps, forgotten database exports, or misbehaving logs. A lesser-known cause is deleted files that remain open by active processes, which can be detected using 'lsof +L1' and resolved by restarting the holding process. Once the culprit is identified, targeted cleanup tools — including Docker pruning, journalctl vacuuming, and package manager cleanup — can reclaim disk space efficiently.