eBPF Filesystem

Plugin: ebpf.plugin Module: filesystem

Overview

Monitor latency for main actions on filesystem like I/O events.

Attach tracing (kprobe, trampoline) to internal kernel functions according options used to compile kernel.

This collector is only supported on the following platforms:

• Linux

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

The plugin needs setuid because it loads data inside kernel. Netada sets necessary permission during installation time.

Default Behavior

Auto-Detection

The plugin checks kernel compilation flags (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT), files inside debugfs, and presence of BTF files to decide which eBPF program will be attached.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per filesystem

Latency charts associate with filesystem actions.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
filesystem.read_latency	latency period	calls/s
filesystem.open_latency	latency period	calls/s
filesystem.sync_latency	latency period	calls/s

Per iilesystem

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
filesystem.write_latency	latency period	calls/s

Per eBPF Filesystem instance

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
filesystem.attributte_latency	latency period	calls/s

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

Compile kernel

Check if your kernel was compiled with necessary options (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT) in /proc/config.gz or inside /boot/config file. Some cited names can be different accoring preferences of Linux distributions. When you do not have options set, it is necessary to get the kernel source code from https://kernel.org or a kernel package from your distribution, this last is preferred. The kernel compilation has a well definedd pattern, but distributions can deliver their configuration files with different names.

Now follow steps:

1. Copy the configuration file to /usr/src/linux/.config.
2. Select the necessary options: make oldconfig
3. Compile your kernel image: make bzImage
4. Compile your modules: make modules
5. Copy your new kernel image for boot loader directory
6. Install the new modules: make modules_install
7. Generate an initial ramdisk image (initrd) if it is necessary.
8. Update your boot loader

Configuration

File

The configuration file name for this integration is ebpf.d/filesystem.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config ebpf.d/filesystem.conf

Options

This configuration file have two different sections. The [global] overwrites default options, while [filesystem] allow user to select the filesystems to monitor.

Config options

Name	Description	Default	Required
update every	Data collection frequency.	5	no
ebpf load mode	Define whether plugin will monitor the call (entry) for the functions or it will also monitor the return (return).	entry	no
lifetime	Set default lifetime for thread when enabled by cloud.	300	no
btrfsdist	Enable or disable latency monitoring for functions associated with btrfs filesystem.	yes	no
ext4dist	Enable or disable latency monitoring for functions associated with ext4 filesystem.	yes	no
nfsdist	Enable or disable latency monitoring for functions associated with nfs filesystem.	yes	no
xfsdist	Enable or disable latency monitoring for functions associated with xfs filesystem.	yes	no
zfsdist	Enable or disable latency monitoring for functions associated with zfs filesystem.	yes	no

Examples

There are no configuration examples.