eBPF DCstat icon

eBPF DCstat

eBPF DCstat

Plugin: ebpf.plugin Module: dcstat


Monitor directory cache events per application given an overall vision about files on memory or storage device.

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


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


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

Performance Impact

This thread will add overhead every time that an internal kernel function monitored by this thread is called. The estimated additional period of time is between 90-200ms per call on kernels that do not have BTF technology.



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



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


All options are defined inside section [global].

Name Description Default Required
update every Data collection frequency. 5 False
ebpf load mode Define whether plugin will monitor the call (entry) for the functions or it will also monitor the return (return). entry False
apps Enable or disable integration with apps.plugin no False
cgroups Enable or disable integration with cgroup.plugin no False
pid table size Number of elements stored inside hash tables used to monitor calls per PID. 32768 False
ebpf type format Define the file type to load an eBPF program. Three options are available: legacy (Attach only kprobe), co-re (Plugin tries to use trampoline when available), and auto (plugin check OS configuration before to load). auto False
ebpf co-re tracing Select the attach method used by plugin when co-re is defined in previous option. Two options are available: trampoline (Option with lowest overhead), and probe (the same of legacy code). trampoline False
maps per core Define how plugin will load their hash maps. When enabled (yes) plugin will load one hash table per core, instead to have centralized information. yes False
lifetime Set default lifetime for thread when enabled by cloud. 300 False


There are no configuration examples.


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 apps

These Metrics show grouped information per apps group.

This scope has no labels.


Metric Dimensions Unit
apps.dc_ratio a dimension per app group %
apps.dc_reference a dimension per app group files
apps.dc_not_cache a dimension per app group files
apps.dc_not_found a dimension per app group files

Per filesystem

These metrics show total number of calls to functions inside kernel.

This scope has no labels.


Metric Dimensions Unit
filesystem.dc_reference reference, slow, miss files
filesystem.dc_hit_ratio ratio %

Per cgroup

This scope has no labels.


Metric Dimensions Unit
cgroup.dc_ratio ratio %
cgroup.dc_reference reference files
cgroup.dc_not_cache slow files
cgroup.dc_not_found miss files
services.dc_ratio a dimension per systemd service %
services.dc_reference a dimension per systemd service files
services.dc_not_cache a dimension per systemd service files
services.dc_not_found a dimension per systemd service files


There are no alerts configured by default for this integration.

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