https://www.pistack.xyz/tags/process-monitoring/ Recent content in Process-Monitoring on Pi Stack Hugo en-us Sat, 23 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-23-linux-open-file-inspection-lsof-fuser-proc-pid-fd-guide/ Sat, 23 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-23-linux-open-file-inspection-lsof-fuser-proc-pid-fd-guide/ <p>When a Linux server runs out of disk space due to deleted-but-still-open files, or when you need to figure out which process is holding a mount point busy during unmount, the ability to inspect which processes have which files open becomes critical. Three approaches dominate this space on Linux: <strong>lsof</strong> (the Swiss Army knife), <strong>fuser</strong> (the quick checker), and direct <strong>/proc/PID/fd</strong> inspection (the kernel-native method). Each serves different operational scenarios — from quick terminal checks to automated monitoring scripts.</p>