A Raspberry Pi 2 is the minimum, I understand it can run on the 1 but can create significant delays in executing actions etc. Given the amount of money you already invested in hardware, an additional 40 bucks would save you quite some frustrations. Other people have openHAB running from their Synology, but I do not have personal experience with that.
This is still also on my to-do list, people argue that the SD card performance deteriorates fast due to excessive reading/writing with the logging of openHAB. So far I did not have any issues, but I am planning to add a USB SSD drive or indeed use a share on my Synology which would work fine. Other people argue when you buy the newest generation/high quality SD cards (you’ll have to Google which SDs fall under this ‘classification’) you should be fine. I would go for the external USB/SSD/Synology drive, there are quite some threads on this forum on that.[quote=“discokrueger, post:1, topic:18257”]
3. If I like to change the Hardware afterwards, should I use a docker-image or set up cloud backup for the config?
SD card (16GB recommended to support wear-leveling)
An SD card is not perfect but an acceptable solution. Why would the nth iteration of the Raspberry Pi still use them as the default most convenient solution if not
It is important to use a bigger SD card for wear leveling and a steady power source to be safe against data corruption. Of course you should still schedule backups. In all my time using multiple RPis over the years (I had one of the very first RPi 1 you had to preregister for) I had only one corrupted SD card. Please also read this great article on the topic: http://hackaday.com/2016/08/03/single-board-revolution-preventing-flash-memory-corruption
That said, there are a lot of solutions to not need to rely on a SD card and if you can share a NFS easily, that would be an option for you.
If you want to switch hardware migration is quite easy. You just have to copy over your openHAB configuration and userdata files (see docs).
I personally run OH in a docker image. It has its pluses and minus. On the plus side you get all the nice migration and isolation that comes with Docker. On the negative side some things that you may want to do with OH won’t work in the Docker container. For example, the Exec binding won’t be very useful to you. The Network dhcp option also won’t work (or at least I’ve not managed to make it work to date).
That being said, openHAB is really well organized which makes it easy to migrate to other hardware. Do I wouldn’t go the Docker route for if that is your only concern.
But countless man hours will go into your config so I recommend, in addition to just making sure it is backed up, to also looking into some sort of software configuration control such as git, subversion, or the like (git seems to be king these days). It is pretty easy to set up a server (I use gogs in a docker container). Not only will this give you a backup of the config, but it will also give you a history of your changes so you can go back and have a document of your changes over time. It really does come in handy.
Great! Thank you very much for the fast and detailed answers!
My Synology is already under heavy CPU load because of other “things”.
I’ll buy a Raspberry 3 and if one of the older NUC’s in my company isn’t used anymore, I’ll switch to it if I’m not happy with the Raspberry and use it as a mediaplayer. I put the storage on the Synology from the beginning. I/O shouldn’t be a problem on the Synology, because CPU usage is limited to 75% for the other things.
Since it is seems to be very easy to backup configurations / whole Raspberry and Docker has some limitations, I won’t use it in the first place.
I’m more on the system engineer side and don’t know git very good, I’ll ask a friend of mine to help me with the git-gogs Server.
I’m pretty excited atm and look forward to the day I can control the first light in my house with openhab. I know it will be a long and hard way, but: "“I have a well-deserved reputation for being something of a gadget freak, and am rarely happier than when spending an entire day programming my computer to perform automatically a task that would otherwise take me a good ten seconds to do by hand.” – Douglas Adams
If you’ll buy a RPi3 you could set it up to boot from a USB flash disk and avoid SD corruption…
That’s what I’m running.
Here’ the link to the official guide to boot Raspberry Pi3 from USB: HOW TO BOOT FROM A USB MASS STORAGE DEVICE ON A RASPBERRY PI 3
You can also boot from NFS if you set up your Synology as a NFS server: NETWORK BOOTING.
All these new boot modes of RPi3 are still in beta, but they’re working flawless - at least for me