The importance of a disaster recovery plan (DRP)

Companies that have suffered a significant loss of data, 43% never reopens, while 29% closes after two years [1]. Computer systems are being increasingly critical and a service downtime of several hours or days directly become in very important economic impact.
Studies with a more holistic approach conclude that for every  1€ of investment in a pre-disaster plan it can mean a saving of 4€  in the response and recovery in the event that it happens [2].
Most SMBs do not have a disaster recovery plan and it is estimated that 25% of them do not reopen after a major disaster.
We will share with you an interesting article where you can deepen more on the subject:

Setup Nagios Server with
nsca-ng for DRLM

One of the methods of error reporting with DRLM is nsca-ng, there is a sample configuration on . In this document we cover the configuration Nagios Server with nsca-ng and also DRLM Server configuration to monitor errors from DRLM Server when running backups.

Of course we assume you have a Nagios Server configured and a DRLM Server

if not, don’t worry, just take a look on the next links

How to install DRLM

How to install NAGIOS

DRLM Server configuration

Install nsca-ng-client package

$ apt install nsca-ng-client

Set up config files

At least 2 files must be configured, in thes example we’re using 3, default.conf has the default values that can be overwritten in local.conf


# REPORT_TYPE=nagios
# These are default values and can be overwritten in local.conf according to your NAGIOS installation and configuration.



Keep an eye on this variable NAGSVC . We’re going to use it on the Nagios server side as a service description it must match.




As you can see this varible was defined previously on default.conf , it is just to show you than it can be overwritten with the /etc/drlm/local.conf file, so if you want, you can dismiss this step.


#### DRLM (Disaster Recovery Linux Manager) Nagios error reporting sample configuration file.
#### Default: /etc/drlm/alerts/nagios.cfg

### identity = <string>
#   Send  the  specified  client identity to the server.
#   By default, localhost will be used.

identity = "DRLM"

### server = <string>
#   Connect and talk to the specified server address or hostname.
#   The  default server is "localhost".

server = "Cervell"

### port = <string>
#   Connect  to  the  specified  service  name or port number on the
#   server instead of using the default port (5668).

port = 5668
password = "change-me"


  • DRLM: Is the name of the DRLM Server
  • Cervell: Is the name of the Nagios Server
  • port: Is the port where the Nagios Server is listening
  • password: Is the default password on the nsca-ng-server

Nagios Server configuration

Once the DRLM Server has been configured we’ll set up the Nagios Server.

Install required packages

$ apt install nsca-ng-server

Set up nsca-ng config files


command_file = "/usr/local/nagios/var/rw/nagios.cmd"

listen = "Cervell" # only listen on localhost. If you use systemd this
                          # this option is overriden by the
                          # nsca-ng-server.socket file.

user = "nagios" # run as user nagios
pid_file = "/var/run/nsca-ng/" # pid file for nsca-ng


authorize "*" {
   password = "change-me"
   # The original NSCA server permits all authenticated clients to submit
   # arbitrary check results.  To get this behaviour, enable the following
   # lines:
           hosts = ".*"
           services = ".*"


This config file has been reduced to only the minimum requirements , if you want to see all options check the original file /etc/nsca-ng/nsca-ng.cfg


Description=NSCA-ng Socket
Documentation=man:nsca-ng(8) man:nsca-ng.cfg(5)



Start nsca-ng-server service

$ systemctl start nsca-ng-server
  • Check the status of the service
$ systemctl status nsca-ng-server
● nsca-ng-server.service - Monitoring Command Acceptor
   Loaded: loaded (/lib/systemd/system/nsca-ng-server.service; static)
   Active: active (running) since Fri 2017-02-17 18:35:46 CET; 5s ago
     Docs: man:nsca-ng(8)
 Main PID: 14495 (nsca-ng)
   CGroup: /system.slice/nsca-ng-server.service
           └─14495 /usr/sbin/nsca-ng -c /etc/nsca-ng/nsca-ng.cfg

Feb 17 18:35:46 cervell nsca-ng[14495]: Ignoring `-b'/`listen' when socket activated
Feb 17 18:35:46 cervell nsca-ng[14495]: nsca-ng 1.4 (OpenSSL 1.0.1t, libev 4.15 with epoll) starting up

Nagios Config files

For this kind of configuration we’re using passive checks, the error notification is set for a limited time using the variable freshness_threshold. It’s importatnt to setup the notifications in order to receibe an email in case of error , if not you could miss it.

  • Add a new service on


define service{
       name passive_service
       active_checks_enabled 0
       passive_checks_enabled 1 # We want only passive checking
       flap_detection_enabled 0
       register 0 # This is a template, not a real service
       is_volatile 0
       check_period 24x7
       max_check_attempts 1
       normal_check_interval 5
       retry_check_interval 1
       check_freshness 1
       freshness_threshold                     600
       contact_groups admins
       check_command check_dummy!0
       notifications_enabled           1                       ; Service notifications are enabled
       notification_interval 10
       notification_period 24x7
       notification_options w,u,c,r
       stalking_options w,c,u
  • Add the DRLM Server on a hostgroup


define hostgroup {
      hostgroup_name  Krbulan-Servers
      alias           Servidors Test
      members         DRLM
  • Add a new check


#NSCA-ng Command
define command{
        command_name check_dummy
        command_line $USER1$/check_dummy $ARG1$
  • Define the host and service


define host{
           use Host-krbulan
           host_name DRLM
           hostgroups  Krbulan-Servers
           alias DRLM

define service{
           use passive_service
           service_description DRLM_Backup
           host_name DRLM
           notifications_enabled           1


service_description has to match with the variable NAGSVC before configured on the DRLM server.

  • Check Nagios configuration files
$ /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Nagios Core 4.2.0
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 08-01-2016
License: GPL

Reading configuration data...
   Read main config file okay...
   Read object config files okay...

Running pre-flight check on configuration data...

Checking objects...
    Checked 16 services.
    Checked 3 hosts.
    Checked 2 host groups.
    Checked 0 service groups.
    Checked 1 contacts.
    Checked 1 contact groups.
    Checked 26 commands.
    Checked 5 time periods.
    Checked 0 host escalations.
    Checked 0 service escalations.
Checking for circular paths...
    Checked 3 hosts
    Checked 0 service dependencies
    Checked 0 host dependencies
    Checked 5 timeperiods
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...

Total Warnings: 0
Total Errors:   0

Things look okay - No serious problems were detected during the pre-flight check

Testing the configuration

From DRLM server exec runbackup (dummy server is not online)

$ root@DRLM:~# drlm -vD runbackup -c dummy
Disaster Recovery Linux Manager 2.1.0 / Git
Using log file: /var/log/drlm/drlm-DRLM-runbackup.20170217.190926.log
ERROR: drlm:runbackup: Client dummy SSH Server is not available (SSH) aborting ...
Aborting due to an error, check /var/log/drlm/drlm-DRLM-runbackup.20170217.190926.log for details

On Nagios


On the notifications we see that the mail has been send


BrainUpdaters takes part in the Backup and Disaster Recovery Devroom at FOSDEM’17

Disaster Recovery management with ReaR and DRLM Workshop

BrainUpdaters team will give a talk about DRLM, an opensource tool for centralized management of Disaster Recovery for Linux.

You will have the opportunity to go deeper into the DRLM (Disaster Recovery Linux Manager) tool and know more about the project history, features, news and a complete workshop on DR management with ReaR and DRLM.


We encourage you to attend to the talk and ask questions to our speaker, Didac Oliveria, co-founder and maintainer at DRLM Project.

Also an informal talk with ReaR, DRLM and Bareos users, about what they would like to implement in future ReaR, DRLM and Bareos versions will be offered to conclude all sessions of the Backup and Disaster Recovery Devroom.

Here more details about the talks and the schedule: