A home automation system in a house soon becomes indispensable, so that it is a real problem when a breakdown occurs. Stopping the management of the heating (necessarily in winter, during your holidays, as Murphy's law requires), shutters that no longer close automatically, simulation of inoperative presence, watering out of order, etc.. The consequences of a breakdown of the home automation system can be numerous, some more critical than others. This is why it could be useful to think about a Disaster Recovery Plan, or “DRP”, as companies do for example.
I. What is DRP?
Those who have worked in business, particularly in IT, are familiar with the term DRP. For others, I invite you to consult for example the page of this company DRP Informatique, which explains the principle very well.
This solution allows you to resume activities as quickly as possible in the event of an incident. DRP is effective in the event of a short outage. All that is required is an assessment of the maximum threshold for downtime and tolerable data loss. It allows you to resume in full or downgraded mode, depending on your business needs. With DRP, any risk that could lead to long-term consequences can be avoided. This formula ensures that operations are restarted as quickly as possible, in an orderly fashion, to resume a normal rhythm as if nothing had happened.
A computer breakdown in a company can be a real tragedy if a DRP has not been put in place: activity on standby, loss of data, etc.. A bit like a breakdown of a home automation system in a house, in fact. This is why it can be interesting to use the principle of the DRP to be able to restart a home automation system quickly.
II. Aspects to be taken into account for a home automation DRP
A home automation system has more or less the same constraints as a conventional computer system. Sensitive points can be located at different levels:
- energy supply
- communication facility
- backup of data
- controller failure (home automation box)
- failure of radio controllers (e.g. Zwave antenna, ZigBee, etc.)
2.1 The power supply
A simple power outage can put a home automation system out of order, either because of a prolonged outage or because of repeated micro cuts that can seriously damage the equipment. Not to mention that a power failure can cut the system's connection with the outside (ADSL box off for example). The simplest remedy is to connect the main components to the UPS: the ADSL box, the router and switch if there is one, the home automation box, its Usb switch if there is one, and if possible the security cameras (the ideal is to use a POE switch that powers IP POE cameras, the switch itself being connected to a UPS, which avoids the multiplication of power supplies). It will of course be necessary to calculate the consumption of the various elements to determine the power of the UPS to be installed. Generally these elements are not very energy consuming, and a 500 to 700VA model should be more than enough to ensure more than half an hour of autonomy (count about a hundred euros).
2.2 Means of communication
A home automation system must be able to communicate with the outside world, either to warn you of a possible problem, or to give you the possibility to control your house remotely (turning on the heating, for example, before returning from holiday). This communication is generally done via an internet box (ADSL or fibre).
In the event of a power failure, communication can be cut off. The solution is the one mentioned above: internet box connected to an inverter.
But the cut can also come from the connection itself: telephone line ripped out in case of storm, NRA failure, see internet box HS. In this case, it is better to plan a secondary communication system:
- some routers offer a dual connection, ADSL + 4G, with the GSM connection taking over automatically in the event of an internet outage. It can be integrated into the router, or as an option, as we added a 3G Usb key to the Synology router.
- if this is not the case, it is possible to connect a 4G router in parallel to the ADSL router
- it is also possible to simply go through a 3G/4G key connected directly to the home automation box if it manages it (example here with an eedomus box and a 3G key).
At home, unfortunately, the GSM connection is not very good, so a 4G backup is not very useful. On the other hand, 2G works perfectly, both for calls and SMS. A Huawei GSM key connected directly to my Jeedom home automation box allows me to exchange with it by simple SMS, either to control it or to retrieve information, especially through interactions. It's a bit “old school”, but it's very reliable.
2.3 Data backup
A home automation system generally records a lot of information, such as consumption monitoring (water, electricity, gas), temperature variations, etc. Let's not forget the configuration and scenarios created. All this data must be saved carefully so that you don't have to reinstall a system from 0.
In the case of a home automation box based on the Cloud (type eedomus for example), these data are generally saved in the Cloud and therefore easily recoverable in case of a box crash.
Some “local” boxes, also sometimes propose to send a backup over the internet, as Jeedom does for example (see our different backup solutions for Jeedom).
The important thing is to have a backup on another support than the home automation box itself, which is not safe from a hardware failure.
2.4 Failure of the home automation box
A hardware failure on the home automation box itself can occur, for various reasons: failure of the power supply of the box, hard drive down, processor down, etc..
The ideal would be to have a home automation box in “spare” (in advance), to be able to quickly replace the hardware, reinject the last backup, and reboot quickly (Jeedom is particularly effective in this area!). This is of course a cost that can not be negligible when it is a box manufacturer type eedomus, Fibaro or other. In the case of a solution available in DIY, like Jeedom for example, it is very simple to prepare a second box using a Raspberry Pi for example. For a quick and inexpensive recovery, this could be a very interesting solution. Those who are more comfortable with computers will be able to install a virtual machine, as we saw by installing Jeedom on a Synology VM. Ideally, two VMs should be installed on two different servers: VMs have the advantage of being easily backed up and easily transferable to another physical machine.
2.5 Radio Controller Failure
Finally, a home automation box often uses a radio controller to communicate with the peripherals, either integrated or external, via a Usb dongle for example.
If the radio controller is integrated, it will be necessary to go back to point 2.4 to replace the box.
If the controller is external, it can usually be replaced by an identical one. Be careful however: some controllers have their own identifier, which will have to be updated, or worse, have in memory all the architecture of the home automation network. I am thinking in particular of the Zwave, whose network, peripheral identifiers, etc. are stored in the Zwave chip of the controller. In other words, if the controller is out of order, you will be good at repairing all your peripherals with a new controller. Depending on your installation, this may take a few hours of work.
Some boxes have provided for the backup of the Zwave configuration, such as eedomus.
On Jeedom, I opted for the Aeotec Gen5 key: it's a Zwave USB key, with a battery, which is already very practical to do its pairing when the peripherals are already in the walls. But above all, the manufacturer offers an application for this key that allows you to make a backup of the whole key, to reinject it into another key if necessary! You just have to make a backup of the key each time you modify your Zwave network, which should not happen every 4 mornings.
By following these few leads, you should be able to ensure a quick recovery of your home automation system. The solutions are of course to be adapted according to the configuration of each one.
For my personal case, my system running around a Jeedom Smart box:
- home automation box, ADSL box, Switch, Synology NAS connected to UPS to cope with power outages
- smartphone with JPI for network monitoring and communication with Jeedom in case of internet outage
- Backing up data to the Synology Nas, itself backed up nightly on Synology's Cloud C2 service
- Jeedom virtual machine on the Nas Synology, with my second Aeotec Gen5 key connected on it, the virtual machine being off (two identical Zwave controllers on the network would be a problem). In case of a hardware crash of my Jeedom box, I can, even remotely, start the Jeedom VM on the Synology, which will reconnect to the Zwave peripherals thanks to its Aeotec key, identical to the one plugged on my Jeedom physical box.
Of course, it takes some knowledge in the field to set all this up, but such a configuration is a priori a test for the majority of problems.
And you, do you have a DRP for your home automation system?