bcc-filelife - Man Page
Trace the lifespan of short-lived files. Uses Linux eBPF/bcc.
Synopsis
Description
This traces the creation and deletion of files, providing information on who deleted the file, the file age, and the file name. The intent is to provide information on short-lived files, for debugging or performance analysis.
This works by tracing the kernel vfs_create() and vfs_delete() functions (and maybe more, see the source) using dynamic tracing, and will need updating to match any changes to these functions.
This makes use of a Linux 4.4 feature (bpf_perf_event_output()); for kernels older than 4.4, see the version under tools/old, which uses an older mechanism.
Since this uses BPF, only the root user can use this tool.
Requirements
CONFIG_BPF and bcc.
Options
- -h
Print usage message.
- -p PID
Trace this process ID only (filtered in-kernel).
Examples
- Trace all short-lived files, and print details:
# filelife
- Trace all short-lived files created AND deleted by PID 181:
# filelife -p 181
Fields
- TIME
Time of the deletion.
- PID
Process ID that deleted the file.
- COMM
Process name for the PID.
- AGE(s)
Age of the file, from creation to deletion, in seconds.
- FILE
Filename.
Overhead
This traces the kernel VFS file create and delete functions and prints output for each delete. As the rate of this is generally expected to be low (< 1000/s), the overhead is also expected to be negligible. 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
Brendan Gregg
See Also
opensnoop(1)