Section 8 · System administration

bcc-mountsnoop.8

Package: bcc-tools

mountsnoop

NAME
SYNOPSIS
DESCRIPTION
REQUIREMENTS
FIELDS
OVERHEAD
SOURCE
OS
STABILITY
AUTHOR
SEE ALSO

NAME

mountsnoop − 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 4.8 feature (bpf_get_current_task()).

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