Australia, Austria, Belgium, Canada, Czech Republic, Cyprus, Denmark, Estonia, France, Germany, Ireland, Israel, Italy, Latvia, Luxembourg, Netherlands, Poland, Spain, Sweden, Switzerland, Turkey, USA – more than 300 attendees and 47 speakers from 22 countries joined us: What would OSMC have been without them? To be honest: Not happening.


….to all our attendees and speakers: You made OSMC special, inspiring and fun by joining or contributing to it! Thanks for your support! 4 days, 3 tracks of talks, 4 workshops, the fun community Hackathon, the Evening Event at Loftwerk, Lambada (former Checkpoint Jenny), Tapasitos, Schimanksi: It was a blast!

Travel back in time

Convince yourselves: Take a look at our Archive with all video recordings of the talks, the speakers‘ slides and conference pictures. And make sure you don’t miss this next year!

Save the date: #OSMC 2019 | November 04 – 07, 2019 | Nuremberg
Julia Hornung

Autor: Julia Hornung

Julia ist seit Juni 2018 Mitglied der NETWAYS-Crew. Vor ihrer Zeit in unserem Marketing Team hat sie als Journalistin und Produktionsassistentin in der freien Theaterszene gearbeitet. Ihre Leidenschaft gilt gutem Storytelling. Privat widmet sie sich dem Klettern und ihrer Ausbildung zur Yogalehrerin.

git gud! or: How I Learned to Stop Worrying and Love my Code

(…and I’m only 13 years late to the party…)

First of all, I have a confession to make. I’m code shy. At least that’s what I thought I was.

One of the fresh-faced young trainees this year here at NETWAYS, I’m not entirely “new” to the scene. Having gone to university (with varied success) I never was bestowed with the confidence to actually contribute to anything. In terms of feedback, my lecturers and I only looked at what I was doing wrong – yes, admittedly, to get me to stop what I was doing wrong, but approaching code like this made me feel like I was always doing something wrong.

Again, admittedly, I probably was always doing something wrong, but I felt like I shouldn’t contribute, I mustn’t contribute, the only thing I would add to an open source project would be bugs, I would mess things up more than I would be helpful to anybody. I’ve written some small stuff for myself at home, but.. why would anybody rely on my code?

It was an awful feeling. So I never did contribute. And that’s how I became code shy.

Three months into my stint at NETWAYS, and it all changed massively. Apart from my wonderful colleagues, git helped in a big way to give me more confidence, to be more active in my participation, to instill a kind of pride in my work I haven’t felt before – to stop worrying and love my code.


So – why write the millionth paragraph about git?

This won’t be a technical introduction, but rather a little recollection of my thoughts and emotions while getting introduced to git and using it at work – because my mind has been thoroughly blown.


What’s git?

Well, let’s take a look at good ol’ Wikipedia:

Git (/ɡɪt/) is a version-control system for tracking changes in computer files and coordinating work on those files among multiple people.

Version-control? Now, what’s that supposed to mean? Is that like back in the days when I sent my source code files to my professor via mail, so he could check over them and see if I did my stuff?

Well, in a way, that could be some sort of version control system as well – just not a very automated and effective one. Version control is about the general management of files, code, data – it keeps track of changes, who did what, when (and if you’re lucky, you’ll even find a hint or two explaining why), and it allows for reversion of changes and modifications people have made.

My ears perked up when I heard this.

I can go around and mess things up and nobody would get mad at me? I won’t break stuff from the get go? I was amazed.


But how does git do it?

At work we have remote repositories hosted on GitLab, from which I could pull all of the files of the project onto my local machine. So now I have my own copy of the project, in which I could move, delete, add or modify files to my liking – and I wouldn’t break anything doing so, because the remote repository on GitLab would be completely unchanged.

In a way, it’s a sandbox for me, where I can go ahead and code, take care of issues, fix bugs, or add features, test them – until I feel safe to share the work I’ve done with other people. You can see how that is a comforting feeling to have – you can code without worries.


So – what happens behind the scenes?

Git takes snapshots of my work. A snapshot is the way git keeps track of all of the files belonging to a project. Git will checksum them, generate a SHA-1 hash. These hashes are the way git knows about the changes to the code inside the files. After I’ve staged my modified files, I can commit the changes I’ve made. Committing will checksum all of the project directories and store them in the repository – and it will store a pointer to the commit that came before it. This is awesome! So now I can have multiple points to revert the project back to, just in case. But… how would I go about doing that?

Well, let’s talk about branches. Branches are pointers to these commits, the default one being the master branch. There is a master branch on my local machine as well as on GitLab – which made me immediately nervous again. But luckily, I can just branch off of my local master, give it a meaningful name, and even push and store the commits belonging to that branch to GitLab, with the master being untouched. Again, another safe environment for me to go about my work, be more assertive in sharing it, all in a peaceful state of mind.

So – thanks to git, I feel safe in being much more creative and independent when going about contributing to our projects here at NETWAYS – and thanks to the awesome work environment here, I do have space and time to try to add to these projects in a constructive way. My colleagues can look at my code, give me tips and hints, and neither them nor me have to worry about me being a nuisance messing things up.

But what if I’ve finally fixed a bug, or added an awesome feature to one of our projects? Then it’s time to make a merge request. On GitLab, I pick a branch of mine, write a little bit about the new functions or which bugs I (hopefully) fixed, and request for these changes to be added into the master. From there, my fate lies in the hands of the project maintainers…

A successful merge request might just be the greatest feeling of all.

I know that there are a million new ways I could break things if I use git wrongly. So, getting good at git is something I must and will learn at NETWAYS. And – bursting with pride and with a newfound confidence – I look forward to learning more every day.

Henrik Triem

Autor: Henrik Triem

Henrik is Anwendungsentwickler in Ausbildung, verhindeter Rockstar, kaffeegetrieben und Open Source-begeistert. Zuhause lässt er es auch mal ruhiger mit Tee angehen, entspannt an Klavier oder Gitarre, erkundet neue Musik oder treibt sich mit seinen Freunden in Deutschland herum.

Ceph Mimic | Using loop devices as OSD

For quite some time we have been using ceph-deploy to deploy OSD in folders during the Ceph trainings held by Netways. This worked perfectly with jewel, but newer versions don’t allow this behaviour anymore.

There are several reasons for this, however, as we have a quite regulated setup for our training notebooks, we had to come up with some kind of workaround. This approach is, while working fine in our training setup, not recommended for production!

The following steps apply to a current CentOS 7 system.

As stated before, we will deploy an OSD on a block device. Though you could use a separate partition for this, we will use a loop device. For this, the first step is to create a file:

For this, create an OSD directory


$ mkdir -p /home/training/my-cluster/osd-$HOSTNAME
$ cd /home/training/my-cluster/osd-$HOSTNAME/

in this folder, create a file for later use

$ fallocate -l 30G 30GB.img

test it

# losetup -l -P /dev/loop1 "/home/training/my-cluster/osd-$HOSTNAME/30GB.img"
# wipefs -a /dev/loop1
# lsblk

This should then display your new loopdevice.

As loop devices are not reboot safe, you need to go some steps further. If you like to use rc.local for this, you’re free to do so.

We’re going to create a service, which will essentially execute the prior mentioned losetup command. For this, we need a script with the command and a .service file, which will execute the script:

sudo losetup -l -P /dev/loop1 "/home/training/my-cluster/osd-$HOSTNAME/30GB.img"

and the service file:

Description=Reattach loop device after reboot

ExecStart=/bin/bash /usr/bin/rebloop.sh


These files have to be executable and be copied to the correct folders. Afterwards, the service must be enabled and can be started.

# chmod +x rebloop.*
# cp rebloop.sh /usr/bin/rebloop.sh
# cp rebloop.service /etc/systemd/system
# systemctl enable rebloop.service
# systemctl start rebloop.service

Ceph, however, will still not want to create an OSD on this device, instead give you following error message:

-->  RuntimeError: Cannot use device (/dev/mapper/<name>). A vg/lv path or an existing device is needed 

You have to make changes to /usr/lib/python2.7/site-packages/ceph_volume/util/disk.py on the OSD host:

in line 201, add “or TYPE==’loop'”:

# use lsblk first, fall back to using stat
TYPE = lsblk(dev).get('TYPE')
if TYPE:
return TYPE == 'disk' or TYPE == 'loop'

and in line 286, change the “skip_loop” switch from “True” to “False”:

 def get_block_devs(sys_block_path="/sys/block", skip_loop=False): 

For testing purposes, simply reboot your system and verify if the loop device gets reattached correctly.

If yes, you can deploy an OSD. We’re using ceph-deploy here:

$ ceph-deploy osd create --data /dev/loop1 $HOSTNAME

When the command was successfully executed on your hosts, you can create your first pool

# ceph osd pool create rbd 100 100 replicated

examine ceph status

# ceph status

tag the pool with an application

# ceph osd pool application enable rbd rbd

As you can see, there are quite some changes to be made, and each of it is failure-prone.

Best practice is to simply use a real block device and for production you really should stick to this.

If, however, there are certain needs to be fulfilled, ceph can be convinced to comply.









Tim Albert

Autor: Tim Albert

Tim kommt aus einem kleinen Ort zwischen Nürnberg und Ansbach, an der malerischen B14 gelegen. Er hat in Erlangen Lehramt und in Koblenz Informationsmanagement studiert, wobei seine Tätigkeit als Werkstudent bei IDS Scheer seinen Schwenk von Lehramt zur IT erheblich beeinflusst hat. Neben dem Studium hat Tim sich außerdem noch bei einer Werkskundendienstfirma im User-Support verdingt. Blerim und Sebastian haben ihn Anfang 2016 zu uns ins Managed Services Team geholt, wo er sich nun insbesondere um Infrastrukturthemen kümmert. In seiner Freizeit engagiert sich Tim in der Freiwilligen Feuerwehr - als Maschinist und Atemschutzgeräteträger -, spielt im Laientheater Bauernschwänke und ist auch handwerklich ein absolutes Allroundtalent. Angefangen von Mauern hochziehen bis hin zur KNX-Verkabelung ist er jederzeit einsatzbereit. Ansonsten kocht er sehr gerne – alles außer Hase!

Monthly Snap October – NET News | Tips & Tricks | DevOps | Events & the WAYS we go

Hey guys,

you might have noticed: OSMC is in full swing! In the month before you could for sure feel the excitement in the air. WHAT THE HACK?! October was full of preparations, writing talks, ordering roll-ups, coding, hacking, getting things done, spreading the #monitoringlove… In the blog we suggested: OSMC: Extend your stay / knowledge!

Some knowledge you could also gain in this month’s tips & tricks section in the NETWAYS blog! Ein paar vim tricks shared Christoph. Lokale Time Machine Snapshots blockieren Speicherplatz told you Georg. Not the pasta-kinda-thing, but Gnocchi: Metriken und Metadaten explained Achim. With Florian you could join an experiment in Wahrnehmungspsychologie im UI Design. And Jean thought On giving up and trying an IDE. While David might have sung With a little Help from my Chef …

Modems and monitors

In the shop too there was a lot going on, as Silke let us know: USB oder RS232? Das LTE Dualport Modem von ConiuGo hat beides! Besides: HW group STE2 – Netzwerk-Thermometer And anyway: Erst testen, dann durchstarten – Unser Netways Monitor! But: Nicht nur Schall und Rauch – Die neue Generation der AKCP Sensoren Wherever you are: Das Office ist nur einen Klick entfernt – Mit dem STARFACE Mobile Client 2.3 Thank you, Silke!

A report from his first team event delivered our new Azubi Tobias in Teamevent 2018: Professional Services. And Dirk shared what it is like to train our new colleagues in Ausbilder erzählt – Professional Services – 2018. Looking for new job opportunities? Visit jobs.netways.de !

The ways we go…

Is there a fair anywhere… IT, Start-Ups, Open Source: You might possibly be meeting Manfred! In October thanks to him: NETWAYS goes to the Dortmund “Initiale”. „Go geht einfach“. Hm, that‘s another thing – from Alexander. More in: The way to Go

The NWS team was happy to announce they started an exciting journey with OpenStack as a Service on nws.netways.de. Get to know more about it here: NWS OpenStack | The ultimate IaaS Platform! And here: NETWAYS Webinare – Jetzt mit OpenStack ! Interested? Pssssst. Apply this code for 45 days free hosted OpenStack: Ge1AL

And now: Back to OSMC!

See you at the conference and the Evening Event in the Loftwerk tonight!


Julia Hornung

Autor: Julia Hornung

Julia ist seit Juni 2018 Mitglied der NETWAYS-Crew. Vor ihrer Zeit in unserem Marketing Team hat sie als Journalistin und Produktionsassistentin in der freien Theaterszene gearbeitet. Ihre Leidenschaft gilt gutem Storytelling. Privat widmet sie sich dem Klettern und ihrer Ausbildung zur Yogalehrerin.


Only 16 days to go?

Time for you to speed up: Grab one of our popular Hackathon tickets and join the event on Nov 08!

It’s fun! You’ll start the day with a short round of introductions, then run a brainstorming session for possible topics in addition to these ones that we came up with so far:


Team up, accept the challenge, collaborate to find a solution, succeed!
Find all details at: osmc.de/hackathon


Taking place on Nov 08 the Hackathon directly follows OSMC’s lecture program. Be part of OSMC and round off your stay! Get your conference and add-on ticket here! We would be happy to see you soon at…

#OSMC | November 5 – 8, 2018 | Nuremberg

Julia Hornung

Autor: Julia Hornung

Julia ist seit Juni 2018 Mitglied der NETWAYS-Crew. Vor ihrer Zeit in unserem Marketing Team hat sie als Journalistin und Produktionsassistentin in der freien Theaterszene gearbeitet. Ihre Leidenschaft gilt gutem Storytelling. Privat widmet sie sich dem Klettern und ihrer Ausbildung zur Yogalehrerin.

On giving up and trying an IDE

I dislike IDEs, at least I tell myself and others that. A 200 line long .vimrc gives a lot more street cred than clicking on a colored icon and selecting some profile that mostly fits ones workflow. So does typing out breakpoints in GDB compared to just clicking left of a line. Despite those very good reasons I went ahead and gave Goland and CLion, two JetBrains products for Go and C/C++ respectively, a chance. The following details my experiences with a kind of software I never seen much use for, the problems I ran into, and how it changed my workflow.

Installation and Configuration

A picture of my IDE wouldn’t do much good, they all look the same. So here’s a baby seal.
Source: Ville Miettinen from Helsinki, Finland

First step is always the installation. With JetBrains products being mostly proprietary, there are no repositories for easy installation and updating. But for the first time I had something to put in /opt. When going through the initial configuration wizard one plugin caught my eye: “IdeaVim”. Of course I decided to install and activate said plugin but quickly had to realize it does not work the same simply running vim in a window.
This “Vim emulation plug-in for IDEs based on the IntelliJ platform” sadly does for one not offer the full Vim experience and the key bindings often clash with those of the IDE. Further I started getting bothered by having to manage the Vim modes when wanting to write code.
I sometimes miss the ability to easily edit and move text the way Vim allows, the time I spend using the mouse to mark and copy text using the mouse are seconds of my life wasted I’ll never get back!

Except for the underlying compiler and language specific things both IDEs work the same, identical layout, window options, and most plugins are shared, so I won’t talk about the tool chain too much. But it needs to be said that Goland just works, possibly because building a Go project seems simpler than a C++ one. Getting CLion to work with CMake is tiresome, the only way to edit directives is by giving them to the command like you would on the shell. This would not bother me as much if CMake didn’t already have a great GUI.

Coding and Debugging

Yet I wouldn’t be still using those programs if there weren’t upsides. The biggest being the overview over the whole project, easily finding function declarations and splitting windows as needed. These are things Vim can be made to do, but it does not work as seamless as it does in the IntelliJ world. It made me realize how little time is spent the actual typing of code, most of it is reading code, drawing things and staring at a prototype until your eyes bleed confusion (sometimes code is not well commented). The debuggers, again specifically the one of Goland, work great! Sometimes I have to talk to GDB directly since there are many functions but too few buttons, but the typical case of setting a breakpoint and stepping through to find some misplaced condition is simple and easy.

Alright, here it is.

There are a few features I have not found a use for yet e.g. code generators and I still manage my git repositories from the shell. The automatic formatting is cool, again especially in Go where there is one standard and one tool for it. Other than that I run into a few bugs now and then, one that proved to be quite a hassle is the search/search and replace sometimes killing my entire window manager. Were it free software, there’d be a bug report. But for now I work around it. Maybe I’ll drop CLion but I doubt I’ll be writing any Go code in Vim anytime soon.

If you think you have found the perfect IDE or just want to share Vim tips, meet me at the OSMC in November!

Jean Flach

Autor: Jean Flach

Geboren und aufgewachsen in Bamberg, inzwischen offiziell Nürnberger. Jean (das "-Marcel" ist still) kam 2014, nach einem Ausflug an die Uni, als Azubi zu NETWAYS. Die Ausbildung ist inzwischen abgeschlossen, aber das Thema Icinga blieb.