Linux › Section H · Processes and resource utilization › Topic H.2
Open files, file descriptors, and lsof
To the kernel, a file, a pipe, a terminal and a network connection all look alike once a process has opened them: each is a small number called a file descriptor. Knowing how descriptors work, and how lsof lists them, solves some of the most puzzling problems an administrator meets.
In this topic
- What a file descriptor is
- Descriptors, open files and redirection
- Seeing descriptors in /proc
- Limits: too many open files
- lsof: listing open files
- Reading the FD and TYPE columns
- Narrowing the output
- Worked example: a filesystem that will not unmount
- Worked example: a full disk that du cannot explain
- Common mistakes to avoid
- Key takeaways
This topic is part of Wuanberri Pro. Checking your access…