Archive for the »Technical« Category

Extended Attributes as user interface – be careful

June 29, 2009 - 10:54 pm

We have decided to use extended attributes in OFS to enable communication between user and filesystem with standard linux tool. Today I came across the first disadvantage of this choice.

I was wondering why gedit claimed that it were not possible to save the backup file. After some debugging I discovered that it tried to copy all extended attributes from the original to the backup file.

In fact, this is a very good idea, especially when using ACLs (which are stored as extended attributes). In OFS we have a little problem with that. Think of setting the “ofs.available” flag to a random file inside the tree. This makes no sense is is denied by OFS. As a result, gedit failes in creating this file.

My fix for this was to hide the ofs.* attributes. This means I removed them from the listxattr FUSE callback, so that they are still available but get not exposed when someone asks for all available attributes.

I don’t know if using attributes which are not visible will raise new problems – time will show…

Category: Linux, OFS  No Comments »

Student project: Cache-manager for OFS

June 18, 2009 - 7:17 pm

Today I visited university again. Three students held a presentation about caching strategies for OFS.

In March Professor Trommler started this project and the students did very good research since then. The approaches are promising and partially close to my own ideas about improvements in OFS.

I’m very keen on the implementation which will start about end of July, after they have finished their exams.

Category: Linux, OFS, Uncategorized  No Comments »

List of bugs and todos for OFS

- 7:05 pm

As promised I’ve posted a set of todos and open bugs to the OFS bugtracker.

I hope I’ll find the time to implement some and can motivate a few people to help me with the others. :)

Category: OFS  No Comments »

Bugtracker and mailing list for OFS

June 11, 2009 - 11:39 am

To improve communication with our users, we set up a mailing list and a bugtracker for the OFS project.

The list works on a mailman based system, provided by sourceforge and since I didn’t like the SF internal tracker, I decided to use mantis for this. Well, I couldn’t find a better point in time to enable mantis. One day later SF announced in a mail, that they will restructure their hosted apps – this means URL will change over the next weeks. Never mind, the old ones will be redirected.

So far – I’ve created a list of TODOs for OFS and will hack them into the bugtracker now.

I encourage you to subscribe to the mailing list to keep up-to-date with the progress of OFS.

Category: OFS  1 Comment »

guug: OFS presentation

May 28, 2009 - 12:00 am

I just returned from University. Professor Trommler and me held a presentation on OFS as we did in Chemnitz. For the first time I showed OFS working with a real remote share not only mirroring a directory on the local machine.

Our presentation took part in a series of monthly presentations organized by sage@guug Nuremberg.

Unfortunately the audience was not very large, but we had good discussions.

Category: OFS  No Comments »

Diploma thesis and Master thesis online

May 24, 2009 - 8:54 pm

Eclipse plug-in using EMF compare on GMF models

Yesterday I uploaded my master thesis. It’s about visualization of differences between EMF models. The compare tool for EMF (Eclipse Modelling Framework) models, which is called EMF compare and the GMF (Graphical Modelling Framework) has been utilized for this thesis. I developed a plug-in, which shows differences in a GMF-like manner.

For more information and download, have a look here.

Open-Source offline-filesystem solutions

In my diploma thesis I compared several network-filesystems and evaluated their offline-features. It has been online for a while, but now I moved it to my new website. I haven’t translated it into english language so it’s available in german only.

Download it here (german only)

Category: Computer, GMF Compare, OFS  2 Comments »

OFS goes Chemnitzer Linux-Tage – one day left

March 13, 2009 - 8:29 am

Hi offline workers,
tomorrow we will present our OFS at Chemnitzer Linux-Tage (Germany).
Professor Trommler and me prepared a presentation and demo of our project. You can meet us on Mar 14th at 12:00am at room V2, learn about concepts in our offline filesystem and see the software in in action.

More information: http://chemnitzer.linux-tage.de/2009/vortraege/detail.html?idx=170

OFS features strongly increased in the past weeks. It is now, finally, an offline filesystem as it is supposed to be. Stay tuned until monday or tuesday when I will merge my working branch into the trunk.

Category: Linux, OFS  1 Comment »