Collectd is a daemon to collect system statistics in RRD (Round-Robin Database) files. It is basically a backend daemon and several front-end exist to navigate through the data.


Collectd is packaged for some Linux distribution. In Debian, this command installs collectd with the default configuration:

apt-get install collectd

The configuration is done in /etc/collectd/collectd.conf. It is quite straightforward and the wiki helps understanding the few tricky fields (

Here is a basic configuration:

LoadPlugin syslog
<Plugin syslog>
    LogLevel info

LoadPlugin cpu
LoadPlugin df
LoadPlugin disk
LoadPlugin interface
#LoadPlugin irq
LoadPlugin load
LoadPlugin memory
LoadPlugin rrdtool
#LoadPlugin sensors
LoadPlugin swap

<Plugin df>
    Device "rootfs"
    # MountPoint "/home"
    FSType "cgroup"
    FSType "devtmpfs"
    FSType "tmpfs"
    FSType "overlay"
    FSType "squashfs"
    IgnoreSelected true
    ReportByDevice false
    ReportReserved true
    ReportInodes true
<Plugin interface>
    # Don't collect statistitics about loopback interface
    Interface "lo"
    IgnoreSelected true
<Plugin rrdtool>
    DataDir "/var/lib/collectd/rrd/"

Network setup

To centralise collected data on a server, you need to use the network plugin ( If your collectd daemon is recent enough, you may use authenticated and encrypted communication channels using a password.

On the server, the configuration looks like this in collectd.conf:

<Plugin network>
    # Server IP and UDP port to listen to
    <Listen "" "25826">
        SecurityLevel Sign
        # This file contains for each user with password "secret":
        #     user: secret
        AuthFile "/etc/collectd/passwd"
        Interface "eth0"
    MaxPacketSize 1024

On each client, collectd.conf may contain:

<Plugin network>
    <Server "" "25826">
        SecurityLevel Encrypt
        Username "user"
        Password "secret"
        Interface "eth0"
    TimeToLive "128"

Collection3 front-end

Collectd package often provides front-end examples among which is Collection3. This front-end is a web front-end written as a CGI script in Perl. By default it will look for RRD files in /var/lib/collectd/rrd but this can be changed by editing etc/collection.conf which contains by default:

DataDir "/var/lib/collectd/rrd"

Collection3 needs some Perl modules:

  • Config::General

  • Regexp::Common

  • HTML::Entities

  • RRDs

On a Debian server, this command installs the needed modules:

apt-get install lib{config-general,regexp-common,html-parser,rrds}-perl

Apache virtual host configuration

<VirtualHost *:80>
    Alias /collection3/ /usr/share/doc/collectd-core/examples/collection3/
    ScriptAlias /collection3/bin/ /usr/share/doc/collectd-core/examples/collection3/bin/
    <Directory /usr/share/doc/collectd-core/examples/collection3/>
        AddHandler cgi-script .cgi
        DirectoryIndex bin/index.cgi
        Options +ExecCGI
        Order Allow,Deny
        Allow from all

Nginx server configuration

server {
    listen 80 default_server;
    location /collection3 {
        alias /usr/share/doc/collectd-core/examples/collection3;
        location ~ ^/collection3/bin/.+\.cgi$ {
            include fastcgi_params;
            fastcgi_pass unix:/var/run/fcgiwrap.socket;
        location /collection3/share {
            try_files $uri $uri/ =404;
        location /collection3 {
            return 301 /collection3/bin/index.cgi;

Lighttpd server configuration

# Note: if the config already enables mod_alias, you must remove it from
# the next line
server.modules += ( "mod_alias" "mod_cgi" )
alias.url += ( "/collection3" => "/usr/share/doc/collectd-core/examples/collection3/" )
$HTTP["url"] =~ "^/collection3" {
    cgi.assign = ( ".cgi" => "/usr/bin/perl" )
index-file.names += ( "bin/index.cgi" )

Collectd Graph Panel front-end

CGP (Collectd Graph Panel) is a better front-end than Collection3. It is written in PHP. To install it, you just need to download latest release from in a folder and to configure your web server accordingly.

Official website:

To enable jsrrdgraph (to have Javascript-rendered graphs in which you can navigate with your mouse), you just need to enable the canvas mode. This is done by creating conf/config.local.php with:

$CONFIG['graph_type'] = 'canvas';

// Here are some other useful options
$CONFIG['graph_type'] = 'hybrid';
$CONFIG['rrd_fetch_method'] = 'async';
$CONFIG['overview'] = array('load', 'memory', 'swap', 'sensors', 'df', 'interface');
$CONFIG['time_range']['default'] = 7200; // 2 hours

A Docker container can be used to “run a PHP webserver in a quick & dirty mode”:

# Dockerfile
# Usage:
#   docker build -t collectd_cgp .
#   docker run --rm -p 80:80 -v /var/lib/collectd/rrd:/var/lib/collectd/rrd:ro -ti collectd_cgp
FROM php:7.4-buster

    export DEBIAN_FRONTEND=noninteractive && \
    apt-get -qq update && \
    apt-get install --no-install-recommends --no-install-suggests -qqy rrdtool && \
    apt-get clean
CMD ["/usr/local/bin/php", "-S", ""]