Ep. 7: Updating Checkmk & using multiple instances

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Note: All the videos on our website offered in the German language have English subtitles and transcripts, as given below.

[0:00:11]	Welcome back to the Checkmk studio.
[0:00:13]	Today’s topic is updates - that is how do I update a Checkmk system to a new version, and while we look at that I will show you another very interesting thing – namely how to run multiple Checkmk instances on a server at the same time.
[0:00:28]	So let's just go back to the Checkmk website, and to the download page.
[0:00:34]	On the download page I will select the Free Edition – which is already pre-selected here because, as you may remember, in the first episode I also worked with the Free Edition, and I would now like to update this to the latest version.
[0:00:47]	For this I choose my operating system – in this case Debian 10, again enter my email address, and download the package.
[0:01:10]	I then copy the downloaded file to my monitoring server as usual, in exactly the same way as in the first episode.
[0:01:25]	I now log in to the server and install the package just as I did in the first episode – in this case, for example, with 'gdebi' - checkmk enterprise p10.
[0:01:54]	So, the package has now been installed, but, the Checkmk instance has not yet been updated to the new version.
[0:02:02]	That is not flaw, rather it is a very important feature of Checkmk – namely that you can install multiple versions in parallel.
[0:02:09]	The next step we need to make now is to switch the instance over to the new version.
[0:02:14]	What is special in Checkmk is that the installation of a new version, and an update of an instance are separate actions.
[0:02:22]	With the 'omd version' command we can display the current Checkmk version, is only half of the information – what you see is in effect the most recently installed version.
[0:02:34]	Much more interesting is the 'omd versions' command, with 's' appended.
[0:02:38]	With which you get a list of all installed versions, one of which is the so-called ‚default version‘, which is normally the most recently installed version and the one which will be used when you create a new instance.
[0:02:51]	We can also see the 1.6.0p7 version here – this is actually the version that runs in the instance that we installed in Episode 1.
[0:03:01]	With the 'omd sites' command you can show all instances - and here can see the 'mysite' instance with version 1.6.0p7.
[0:03:10]	I have already mentioned that with Checkmk one can operate multiple instances simultaneously.
[0:03:13]	Later I will show you how that works.
[0:03:16]	We first need to update this instance to the new version.
[0:03:19]	To get the new version into the instance, first we must stop the instance.
[0:03:24]	With the 'omd status' command I can get an overview.
[0:03:30]	The instance is running - you can see that I have executed the command as 'root' with the instance name. You always have this option so that you don't need to log into the instance.
[0:03:38]	It is running. So, first I will stop it, because for an update that is, of course, a prerequisite, and I simply enter the 'omd update mysite' command and next receive the notice that an update from 1.6.0p7 to 1.6.0p10 will be performed.
[0:04:01]	If you have more than two versions installed, you will be asked which of the version you want to update to.
[0:04:09]	I'll just confirm the update, then a couple of configuration files will be adjusted and the update will be completed.
[0:04:20]	Then with 'omd start mysite' I can start the instance again.
[0:04:29]	Once the instance has restarted, I will simply go back to the web overview and log in and as you can already see in the login window the version 1.6.0p10 is already shown, so I'm already on the new version, so I don't need to do anything more and can continue as normal.
[0:04:50]	My monitoring is running and everything is as usual.
[0:04:55]	At the beginning, I told you that I would show you how to run multiple instances on a Checkmk server in parallel and that is really very easy.
[0:05:04]	Actually, we do nothing more than we did the first time, namely that we create another instance with the 'omd create' command, and I now enter 'mysite2' as the name, for example.
[0:05:17]	It is always very practical if you change the password right away, I do it like the first time as an instance user by simply copying this command from here and assigning a password of my choice.
[0:05:31]	And now I start the instance - since it won't start automatically.
[0:05:37]	Because I am the instance user, I don't need to specify the instance name and once it has started, I can log in on the web overview as normal.
[0:05:49]	For this I naturally need the IP address: 10.1.2.73 and now, of course, the name of the new instance - in this case 'mysite2' and as usual you will find an empty instance.
[0:06:08]	These two instances, which are now running on the system, work completely in parallel to each other, have no influence at all on each other apart from simply requiring resources from the computer.
[0:06:18]	So, it's kind of like virtualization, but a lot easier since you don't need VMware or anything like that, you simply have two instances running in parallel.
[0:06:26]	In practice, for example, it is very popular to have an installation for trying out new things, for example to test a new version of Checkmk and only when you are satisfied and have tried everything out switch the production instance over to the new version.
[0:06:44]	So, that was it for today. As you have seen, an update is not difficult to make.
[0:06:47]	I hope we see each other again soon, in the next episode. So until then, I wish you all the best.
[0:06:51]	Ciao!