How to release Linux disk space

Article Title: how to release Linux disk space. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

Yesterday, I helped my colleagues solve a difficult problem that the disk space was "invisible" and kept a brief record.

1. Use df to check whether the available space in the/root directory is 0.

[Root @/] # df-h

2. Use the du check to find that each directory occupies a small amount of space, and about 3G space is inexplicably lost.

[Root @/] # du-m? Max-depth = 1 | sort-gr

3. Check with lsof to find out that a file is deleted and the process is still alive, resulting in space occupation.

[Root @/] # lsof | grep delete

Based on the process numbers listed in lsof, after killing these processes, the space is released.