mountsnoop man page

mountsnoop ā€” Trace mount() and umount() syscalls. Uses Linux eBPF/bcc.

Synopsis

mountsnoop

Description

mountsnoop traces the mount() and umount() syscalls, showing which processes are mounting and unmounting filesystems in what mount namespaces. This can be useful for troubleshooting system and container setup.

This works by tracing the kernel sys_mount() and sys_umount() functions using dynamic tracing, and will need updating to match any changes to this function.

This makes use of a Linux 4.4 feature (bpf_perf_event_output()).

Since this uses BPF, only the root user can use this tool.

Requirements

CONFIG_BPF and bcc.

Fields

COMM

Process name

PID

Process ID

TID

Thread ID

MNT_NS

Mount namespace inode number

CALL

System call, arguments, and return value

Overhead

This traces the kernel mount and umount functions and prints output for each event. As the rate of these calls is generally expected to be very low, the overhead is also expected to be negligible. If your system calls mount() and umount() at a high rate, then test and understand overhead before use.

Source

This is from bcc.

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS

Linux

Stability

Unstable - in development.

Author

Omar Sandoval

See Also

mount(2) umount(2)

Info

2016-10-14 USER COMMANDS