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XtreemOS tutorial at EuroSys 2010

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In April 2010 XtreemOS will have a half-day tutorial at the EuroSys conference.

We'll present and demonstrate the main features of XtreemOS, reflecting the progress that has been made with the last release.

We are welcoming users and developers of distributed applications, and also Grid system administrators, to participate to this tutorial. The attendees will learn how to use XtreemOS for executing and developing complex applications, for storing distributed data and for managing virtual organizations in a simple way. We hope everybody will enjoy discovering XtreemOS!

The tutorial will be presented by: Corina Stratan (VUA), Massimo Coppola (CNR) and Guillaume Pierre (VUA).

More details on the conference web site:



XtreemOS videos on YouTube


Luscious Lebkuchen: XtreemFS 1.2 now available

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XtreemFS 1.2 ("Luscious Lebkuchen") is now available at

New features:
  • asynchronous MRC database backups (database dumps are created in the background)
  • new GRID SSL mode: SSL is used for authentication only, data is transferred via plain TCP for a better performance
  • Vivaldi-based replica selection and placement
  • MRC and OSD wait and retry for a configurable time span if they cannot reach the DIR on startup
  • faster file copying of files with 'cp' (by providing correct values for 'st_blksize' with 'getattr')
  • additional binaries with standard Unix names (mount.xtreemfs, mkfs.xtreemfs, lsfs.xtreemfs, rmfs.xtreemfs)
  • experimental Hadoop file system driver for XtreemFS
  • web-based admin console
We also fixed most of the bugs recorded in the tracker.


When upgrading your XtreemFS installation from 1.1 to 1.2, MRC and DIR databases should be converted automatically, without the need for human intervention. However, for safety reasons, we suggest to create an XML dump with the old release before updating; see "Updating" section in the XtreemFS FAQs (


XtreemOS is on Facebook! ;-)

XtreemOS has its own facebook page!

It's worth mentioning that this Facebook page was created by someone external to the project - what a good idea...and thank you! ;-)

Wanna join the XtreemOS group on Facebook?


XtreemOS at SuperComputing 2009

XtreemOS exhibited for the 3rd time this year at Supercomputing '09 in Portland, Oregon. Sharing the booth were consortium partners INRIA, CNR, VUA, ZIB and Kerlabs.

During the show, the new version 2.0 of XtreemOS was demoed (along with the latest version of Kerrighed using their cluster in a box). Interest from visitors ranged from university faculty interested in integrating XtreemOS in their teaching to other research institutions wishing to join future development.



Despite the economic crisis, there were not many signs of retrenchment in investment or research in HPC (high performance computing). A number of ambitious future projects were unveiled at Supercomputing, along with record numbers of visitors.

One other highlight from the show was the keynote from former U.S. Vice President AL Gore, who addressed the topic of how supercomputing can be used to harness solutions to global climate change science.

Already, space for SC '10 is nearly sold out, which portends another record breaking exhibition.


XtreemOS in the news

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XtreemOS 2.0 release announcement


Get acquainted with one XtreemOS partner: Ulm University (UULM)

Ulm University is located in the southern part of Germany. It was founded in 1967 and is therefore a rather young university. Nowadays there are about 7 000 students with main subjects in medicine, natural sciences, mathematics, economics, engineering and computer sciences. The computer science department has about 20 professors doing research and teaching in all major areas of computer science. Ulm University is partner of XtreemOS with the Aspectix Research Team as part of the Institute for Distributed Systems. The team and its 7 researchers are working on multimedia platforms, middleware systems for adaptive applications and fault tolerance.



UULM contribution to XtreemOS


  • Virtual Nodes

The main task of UULM in XtreemOS is the development of a fault tolerance infrastructure called Virtual Nodes that can be used for grid applications but also for XtreemOS-internal services. Virtual Nodes are a framework providing multiple configurable implementations for replication support, e.g., Virtual Nodes provide active and passive replication protocols. The most innovative element of Virtual Nodes is the support of concurrency for replicated services due to different deterministic scheduling algorithms. For adding new replicas a special join protocol was developed that supports consistent state checkpoints even with concurrent service activities. Current work is the integration of Virtual Nodes technology into the XtreemOS job management services. The integration into security services is under consideration.

  • Distributed Servers

In cooperation with Vrije Universiteit Amsterdam (VUA), UULM has contributed to the Distributed Server system that allows clients to use a fixed server address. The corresponding server socket can be moved between different server instances. UULM is working on the integration of Distributed Server technology with Virtual Nodes, which allows clients to remain completely agnostic about replication.

XtreemOS 2.0 release now available!

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XtreemOS 2.0 Release


Rennes, France Nov 12, 2009The XtreemOS project has released the second public release of its Linux-based Grid operating system under the motto "Making Grid Computing Easier". The consortium has conceived and integrated a platform of open source technologies to enable easier usage, management, scalability and programming on top of Grid computing resources.


XtreemOS brings new capabilities to Grids, such as easing job submission and monitoring, while providing a comprehensive security implementation and virtual organization management. XtreemOS comes in three flavours: The PC flavour makes it possible to aggregate standalone PCs as computation resources into XtreemOS Grids. The XtreemOS cluster flavour is based on Kerrighed's LinuxSSI (single system image) technology. LinuxSSI is a Linux cluster providing users an image of a single large system. The third flavour, XtreemOS Mobile has been tailored to run XtreemOS services on mobile devices, such as Nokia Internet Tablets.


The 2.0 release version includes the following functionalities:


    Creation and management of dynamic virtual organizations The security infrastructure includes a set of services that guarantee the secure operation of the system, providing management of credentials, permissions and resources.


    Application execution management AEM is able to search available nodes that fulfill the application needs from within a large number of candidates and then execute the application on the selected nodes. AEM provides job and resource monitoring so that users can get a Linux-like view of their applications. A new experimental feature in this release is the ability to run interactive jobs such as graphical applications unmodified; harnessing the power of a Grid system. In addition, there is a new graphical tool for editing and managing job submissions. Lasty, grid checkpointing and job migration has been integrated into this version.


    XtreemFS is a replicated and distributed object-based file system. It allows scaling an installation by adding machines with free storage resources. It offers striping of files over multiple storage servers for high performance parallel access. Furthermore, it supports automated mounting of home volumes.


    XOSAGA programming interface The XOSAGA API is built using the Simple API for Grid Applications (SAGA) standard from the Open Grid Forum (OGF). It provides access to XtreemOS resources and services.


    Xosautoconfig is a new tool included in the distribution, which assists Grid administrators and other users to quickly deploy XtreemOS nodes on Virtual Machines, Grids and test beds.


With this release, the XtreemOS consortium invites the participation of external contributors and feedback. XtreemOS is open source and GPL/BSD licensed. For more info please email: There is a lively developer channel on #xtreemos-dev on, as well.


Getting XtreemOS

The second public version based on Mandriva Linux isos can be downloaded from the project website: software. The source code is available at Also available in the distribution are sample applications and demos.


About XtreemOS

Partially funded by the sixth framework programme (Contract FP6-033576) of the European Commission, XtreemOS is a 4-year research project, comprised of 19 academic and enterprise partners in Europe and China that aims to develop a Linux based grid operating system to simplify the usage, management and programming of grids.





Slides of summer school available online!

The first XtreemOS summer school took place in Oxford, UK, last September 7-11, 2009.

The presentation slides are now available here (in technical programme).


Get acquainted with one XtreemOS partner: Barcelona Supercomputing Center (BSC)

 Early in 2004 the Ministry of Education and Science (Spanish Government), Generalitat de Catalunya (local Catalan Government) and Technical University of Catalonia (UPC) took the initiative of creating a National Supercomputing Center in Barcelona. BSC-CNS (Barcelona Supercomputing Center – Centro Nacional de Supercomputación) is the National Supercomputing Facility in Spain and was officially constituted in April 2005. BSC-CNS manages MareNostrum, one of the most powerful supercomputers in Europe, located at the Torre Girona chapel. The mission of BSC-CNS is to investigate, develop and manage information technology in order to facilitate scientific progress. With this aim, special dedication has been taken to areas such as Computational Sciences, Life Sciences and Earth Sciences.

All these activities are complementary to each other and very tightly related. In this way, a multidisciplinary loop is set up: our exposure to industrial and non-computer science academic practices improves our understanding of the needs and helps us focusing our basic research towards improving those practices. The result is very positive both for our research work as well as for improving the way we service our society.


XtreemOS overall architecture


BSC contribution to XtreemOS


  • Application execution management

The main task of BSC in XtreemOS is to lead the research and development of the Application Execution Management (AEM) module. This module is in charge of setting the whole environment to run jobs in the grid (build reservations, allocate resources, schedule jobs, launch processes, etc.) and to control and monitor them (maintaining the state, allow thread-level monitoring, etc.).


Specifically BSC is highly involved in the scalable job management avoiding any kind of bottleneck as well as on the monitoring that allows users to monitor a job just as if it were a Linux process (you can even monitor the change of thread states). 

  • XtreemFS

 In the data management module, the storage system research group is in charge of the algorithm to locate the best replica of a file as well as to decide when and where replicas should be created and/or removed. This mechanism is base on an improved version of the Vivaldi algorithm that places all XtreemOS nodes into a 2D space based on communication latencies.

  • Mobile-device flavor

Regarding mobile devices, BSC is cooperating with TiD to build the embedded version of XtreemOS to be run on mobile devices. Mainly, BSC is working on the AEM and XtreemFS modules of XtreemOS-G for these devices. 

  • Applications 

Finally, BSC is porting two applications trying to take full advantage of the benefits of this new system. These applications are specweb 2005 and hmmpfam which runs on top of COMPSs a workflow manager that is also ported to its full efficiency to XtreemOS by BSC.



XtreemOS 2.0 coming soon!

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After several months of hard work and testing the XtreemOS consortium is pleased to announce a release candidate of XtreemOS 2.0.

Among the many improvements:

  • New graphical tools to install and manage XtreemOS.

  • Interactive Job Sessions - Run unmodified graphical applications on a grid.

  • Enhanced job management with the ability to make resource reservations.

A final 2.0 release is expected soon in ISO and virtual machine formats.

XtreemOS 2.0 will inlcude new, advanced features and more differentiating factors than XtreemOS 1.0. It will also be significantly easier to install and configure.

Download for XtreemOS-RC5 and RC6 here:
The RC5 version for 64 bits and RC6 for 32 bit are identical in content.


XtreemOS at Poslovna Linux Konferenca

Poslovna Linux konferenca (Business Linux Conference) is an annual event in Slovenia, focussing on the use of Linux and other open-source software in business environments.  This year  the conference took place in Portorož on the 28th and 29th of September.



XtreemOS was presented by Marjan Šterk and Matej Artač (both from XLAB) as a platform for collaboration both within companies and across company borders. A potential use case in an architectural bureau was used to enumerate the most important features of XtreemOS in businesses: sharing files with XtreemFS, exploiting grid resources for automatic compilation of project documentation, marketing material, animations etc, and use of applications installed on remote computers without the need for local user accounts. A simplified live demonstration of these features was also shown.

XtreemOS general meeting in Valladolid

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From 6th to 9th October, a General Technical Meeting was organized at Telefonica I+D premises in Valladolid, Spain.

With a large participation of around 40 people, the meeting was very productive, including many sessions devoted to security aspect, as well as XtreemOS file system, changes in AEM, etc. Plenary sessions for developers (specially focused on release 2.0 and also the future 2.1 release before Christmas), for demos and also for performance evaluation were also important in the agenda.

TID meeting

But not everything was just work, and the partners have enjoyed some activities "out-of-agenda", like a guided tour in Valladolid and the social event in Bodegas Arzuaga, one of the best wineries in the region (Ribera del Duero), where we visited the cellar and also enjoyed a dinner with the typical "lechazo" (young lamb) from Castilla. With a special mention also for "tapas": some XtreemOS members became experts and practiced this "regional sport" in even 5 different bars in just one night!

Tid meeting2

It is interesting to mention as well the visit from the chairman of Telefonica I+D premises in Valladolid, taking the opportunity to take some photos and to write a press release that will be published internally in Telefonica and also in regional newspapers.



Feedback: XtreemOS summit at Euro-Par 2009

Delft, The Netherlands - August 25, 2009

The first XtreemOS summit was co-located with Euro-Par 2009 in Delft, The Netherlands.


The objective of this half-day summit was to present the XtreemOS technology with different talks ranging from a general overview to selected topics including security, resource matching, and parallel I/O. After the talks different demonstrations were run to show the benefits of  the XtreemOS system.

The summit concluded with an interesting and fruitful discussion between the audience and the XtreemOS representatives.

XtreemOS summit webpage: here

Thilo Kielmann (VUA) also gave an invited talk at CoreGRID 2009 workshop (in conjunction with EuroPar): "XtreemOS a sound foundation for IaaS and cloud federations"

In addition, John Mehnert-Spahn (UDUS) presented an XtreemOS paper:

- "The Architecture of the XtreemOS Grid Checkpointing Service" by John Mehnert-Spahn, Thomas Ropars, Michael Schoettner and Christine Morin



XtreemFS in the news

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Release 1.0 of XtreemFS

XtreemFS 1.0 is out. XtreemFS now supports read-only replication with failover, data center replica maps, parallel reads and writes, and a native Windows client, among other new features.

Download it at

Watch our demo of replication and failover on youtube!

We demonstrate the XtreemFS replication and failover with an unmodified MPlayer. We play a regular movie file stored on two XtreemFS OSDs.



XtreemOS at Libre Software Meeting (RMLL'09)

Rencontres Mondiales du Logiciel Libre 2009 in Nantes, France

In 2009, LSM took place between July 7th and July 11th in Nantes, France ! An event managed by the Linux-Nantes Association, with active support from Free, Libre and Open Source Software users’ associations from the whole country.

On July 8th 2009, Surbhi Chitre of INRIA, Rennes gave a talk at RMLL'09 Nantes on OpenVZ integration in XtreemOS. She explained the need of XtreemOS, its importance as a solution to make grids easy and also the features that XtreemOS offered along with why and how it was new.

She illustrated her design of OpenVZ integration in XtreemOS, the difficulties in doing so and why OpenVZ was chosen for integration in XtreemOS.

Surbhi's presentation slides are available here.

RMLL'09 website:



XtreemOS at Linux Symposium

The Linux Symposium was held at Montreal, Canada, from July 13th to July 17th.


John Mehnert-Spahn (UDUS) gave a technical presentation of 45 minutes on his work "Incremental Checkpointing for Grids" on July 15th. John explained the motivation behind incremental checkpoint and its implementation in Linux SSI as well as its integration in XtreemOS. There was much interest in the implementation of incremental checkpoint. 

Linux Symposium 2009 - John

On 17th July Surbhi Chitre (INRIA) held a BOFs session for XtreemOS. She explained why XtreemOS is attractive and how it is a complete solution for grids. She also explained her work of integrating OpenVZ in XtreemOS, why it was chosen and the challenges in doing so. In her talk, she also gave a brief introduction to XtreemFS features. This was followed by a presentation by Louis Rilling of Kerlabs of Kerrighed Clusters which is supported by XtreemOS.

Linux Symposium 2009 - Surbhi


XtreemOS summer school: extended registration deadline!

The deadline to register for the first XtreemOS summer school has been extended to August 5th, 2009.

The deadline for grant request is now over (July 26th) and all the available grants have already been awarded.

School participants are encouraged to give a presentation of their research work during the doctoral symposium (Sept. 10th): if you want your presentation to be considered by the PhD organization committee, please send us the title of your talk and a one-page abstract to by August 24th.

Reminder: There will be an award to the best presentation!



XtreemOS at LinuxTag 2009

June 24-27, 2009

LinuxTag is Europe's leading event for Linux and free software. The four-day event has been taking place annually on the Berlin Exhibition Grounds since 2007. A total of 10,780 visitors from around the world attended LinuxTag 2009 in Berlin.

We presented XtreemOS and XtreemFS with a community booth at LinuxTag 2009 in Berlin.


During the four days of the exhibition we had a chat with about 60 visitors. For us it was very interesting to see what kind of problem the people had in mind to solve with XtreemFS. This ranged from using XtreemFS to replace VPN+Samba to video recording, editing and replication for streaming. Of course, there was quite some interest in using XtreemFS as a kind of cloud storage.

More than 10,000 visitors make LinuxTag the largest industry event in Europe - Wider-ranging conference programme and greater international participation (135 exhibiting companies and projects and around 300 speakers).

LinuxTag website

The next LinuxTag will take place from 9 to 12 June 2010 in Berlin!