Last weekend, I traveled to the beautiful city of Brno in the Czech Republic, to attend at speak at the DevConf.CZ open source conference. I had submitted a talk about our ongoing work on the Ceph Manager Dashboard and was very happy that it got accepted, as I haven’t been to a DevConf before.

The conference took place in the lecture halls of the Faculty of Information Technology at Brno University of Technology, which provided a very nice venue with lots of rooms and infrastructure (the WiFi was a tad bit slow, but usable). Still, some talks were so popular that the rooms were full and the session chairs had to block others from entering (something that other conferences like FOSDEM also suffer from). Fortunately, many of the sessions were recorded, so there is an opportunity to watch them later.

The overall organization of the conference was excellent, the organizers had really thought of everything and it was a pleasure to attend this event from a speaker/participant point of view. There was a cloak room, badges that clearly indicated your preference of being photographed or your preferred level of engagement in conversations with other attendees. Food was also available in good variety (both free and several paid-for additional options provided by food trucks). The organizers had also set up a group chat on Telegram, which was used to spread information to all participants quickly.

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My talk Ceph Management and Monitoring with the Dashboard was scheduled for Saturday, 16:00, so I had some time to attend other sessions before and afterwards.

The session schedule was packed and I had a tough time to choose which ones to attend. I ended up with attending the following sessions:

  • Growing Your Career: From Tactical to Strategic — The topic sounded interesting, but I only attended this panel discussion for about 20 minutes, as it was too painful for me to watch how a single lapel microphone was frequently handed over from one panelist to another one so they could be heard. Even a handheld mike would have been an improvement…
  • A Greybeard’s Worst Nightmare — in this session, Daniel Riek summarized the pains of packaging modern applications, the proliferation of custom solutions for distributing software and libraries and how they could be addressed in the modern world of container technologies. Good food for thought, it certainly resonated well with some experiences we have been going through in the openATTIC and Ceph Manager Dashboard project.
  • Open leadership: An invitation to all — this presentation resonated very well with me and I was able to capture a number of good ideas on how to improve my own skills. I liked the style of this session, which was more an open conversation than a head-on presentation. To my knowledge it wasn’t recorded, but the slides are worthwhile checking out.
  • Ceph data services in a hybrid cloud world — Sage Weil, founder and lead developer of the Ceph project talked about the challenges of syncing and moving data across multiple clouds and explained some of the existing and future solutions that Ceph brings to the table to resolve these. I found this session very insightful and it was interesting to learn more about the project’s future plans in this area. I guess our work on the Ceph Manager Dashboard isn’t finished any time soon!
  • Active/Active NFS Serving over CephFS — Jeff Layton gave a very detailed into his work on making it possible to set up NFS services based on NFS Ganesha with CephFS on the backend in a scalable way, this was very insightful (see his blog post for an example on how to set this up). Unfortunately his live demo failed during the presentation with processes getting stuck, but I actually saw the demo before his session and it certainly impressed me!

Unfortunately I could only attend the conference on Saturday, as I was traveling to and back from the event by train on Friday and Sunday. I wished I could have stayed for more! I will definitely plan to go back there some time.

I took a few pictures during the event, which can be found on Flickr :

DevConf.CZ, Brno (CZ), 2019-01-26

More pictures can also be found here and here.

In summary, I had a great time at DevConf.CZ and I can only highly recommend to plan on attending it if you get a chance!

Last week, I attended the 13. Kieler Open Source und Linux Tage (KieLux) in Kiel, Germany, to give a presentation (in German) about “Flexibles Storage Management unter Linux mit OpenATTIC. I had an audience of ~25-30 people, a video recording of the session (in 4K!) will be published shortly. I had a great time at KieLux and learned a lot in the other sessions I attended. It was also nice meeting new people and touching base with long-time acquaintances again. Thanks to the KieLux organizers for arranging this event and for inviting me!

My slide deck is now available from SlideShare. Enjoy!

Last weekend, I gave a presentation titled “The Evolution of Storage on Linux” at this year’s FrOSCon 10 conference (Happy Anniversary!). In case you have missed it, you can find the slides and video recording below. Thanks to the FrOSCon team for having me, it’s always a pleasure to be there!

Unfortunately I had some technical issues in the beginning and was somewhat too ambitious with regards to the topics I wanted to cover, so I ran out of time. There is simply too much cool stuff happening in the storage space – but I hope that the audience still enjoyed it!

Slide deck:

Video:

While virtualization makes it pretty easy to spawn up new VMs quickly (e.g. for load balancing purposes), I always felt that providing concurrent file-based access to the same data to these VMs has been somewhat cumbersome, even though it’s still a requirement for many applications that need to share data between parts of the application, or multiple instances thereof.

If you didn’t have some kind of SAN/NAS solution in your data center, it usually involved quirks creative solutions on the VM side (e.g. setting up a VM instance that acted as a central file service via NFS/SMB, or using a shared disk file system like GFS2 or OCFS2). But even if you did, the underlying virtualization technology did not provide any integration or API-based approach to this (at least that was my impression).

I recently stumbled over Amazon’s Elastic File System (EFS), which was announced on April 9th, 2015. EFS provides shared storage as a service (STaaS) via the NFSv4 protocol. This makes it pretty easy to mount the same share on multiple (Linux-based) VMs. Amazon only charges you for the storage that you actually use (billed monthly, based on the average used during the month), and the use of SSDs should make sure that latency (IOPS) does not suck too badly.

Interestingly, Microsoft has been offering something similar for almost a year now: Azure File Service was announced on May 12th, 2014 already. It provides shared access to files via the SMB protocol (which makes it suitable for both Windows and Linux-based VMs). In addition to that, Azure File Service also provides a REST API to access and manage objects stored on this service, which makes this service more versatile/flexible. Similar to Amazon, Microsoft only charges for the disk space you actually use.

Note that both EFS and Azure File Service are still labeled as “Preview” at the time of writing and have certain limitations you should be aware of (Unsupported NFSv4.0 Features in EFS, Amazon EFS Limits During Preview, Features Not Supported By the Azure File Service) – so make sure to have backups of any data you store on them 🙂

The Open Source community has noticed the requirement for shared file access, too – Red Hat recently announced their participation in OpenStack’s Manila project, which provides a shared file service for this emerging cloud technology. From what I can tell, Manila’s focus currently is more on providing shared storage for OpenStack compute nodes, it’s not entirely clear to me yet if there are any plans to establish this as a solution to provide shared file systems to virtual machines as well (in addition to the object and block storage capabilities they already offer).