Browsing by Author "Nou Castell, Ramon"Més informació

Now showing items 1-20 of 20

    • Adaptive request scheduling for the I/O forwarding layer using reinforcement learning 

      Bez, Jean Luca; Zanon Boito, Francieli; Nou Castell, Ramon; Miranda Bueno, Alberto; Cortés, Toni; Navaux, Philippe O.A. (Elsevier, 2020-11)
      Article
      Restricted access - publisher's policy
      In this paper, we propose an approach to adapt the I/O forwarding layer of HPC systems to applications’ access patterns. I/O optimization techniques can improve performance for the access patterns they were designed to ...

    • Automatic I/O scheduler selection through online workload analysis 

      Nou Castell, Ramon; Giralt, Jacobo; Cortés, Toni (2013)
      Conference report
      Open Access
      I/O performance is a bottleneck for many workloads. The I/O scheduler plays an important role in it. It is typically configured once by the administrator and there is no selection that suits the system at every time. Every ...

    • DYON: Managing a new scheduling class to improve system performance in multicore systems 

      Nou Castell, Ramon; Giralt Celiméndiz, Jacobo; Cortés, Toni (Springer, 2013)
      Conference report
      Open Access
      Due to the increase in the number of available cores in current systems, plenty of system software starts to use some of these cores to perform tasks that will help optimize the application behaviour. Unfortunately, current ...

    • ECHOFS: a scheduler-guided temporary filesystem to leverage node-local NVMS 

      Miranda, Alberto; Nou Castell, Ramon; Cortés, Toni (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      The growth in data-intensive scientific applications poses strong demands on the HPC storage subsystem, as data needs to be copied from compute nodes to I/O nodes and vice versa for jobs to run. The emerging trend of adding ...

    • Energy-aware scheduling in virtualized datacenters 

      Goiri Presa, Íñigo; Julià Massó, Ferran; Nou Castell, Ramon; Berral García, Josep Lluís; Guitart Fernández, Jordi; Torres Viñals, Jordi (IEEE Computer Society Publications, 2010)
      Conference report
      Open Access
      The reduction of energy consumption in large-scale datacenters is being accomplished through an extensive use of virtualization, which enables the consolidation of multiple workloads in a smaller number of machines. ...

    • Energy-efficient and multifaceted resource management for profit-driven virtualized data centers 

      Goiri Presa, Íñigo; Berral García, Josep Lluís; Fitó, Josep Oriol; Julià Massó, Ferran; Nou Castell, Ramon; Guitart Fernández, Jordi; Gavaldà Mestre, Ricard; Torres Viñals, Jordi (Elsevier, 2012-05)
      Article
      Restricted access - publisher's policy
      As long as virtualization has been introduced in data centers, it has been opening new chances for resource management. Nowadays, it is not just used as a tool for consolidating underused nodes and save power; it also ...

    • Freezing Time: a new approach for emulating fast storage devices using VM 

      Bona, Luis C.E.; Elias, Alessandro; Ziviani, Andre P.; Cortés, Toni; Nou Castell, Ramon; Alves, Marco A.Z. (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      Recently we are seeing a considerable effort from both academy and industry in proposing new technologies for storage devices. Often these devices are not readily available for evaluation and methods to allow performing ...

    • GekkoFS: A temporary distributed file system for HPC applications 

      Vef, Marc-André; Moti, Nafiseh; Süb, Tim; Tocci, Tommaso; Nou Castell, Ramon; Miranda, Alberto; Cortés, Toni; Brinkmann, Andre (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      We present GekkoFS, a temporary, highly-scalable burst buffer file system which has been specifically optimized for new access patterns of data-intensive High-Performance Computing (HPC) applications. The file system ...

    • Heterogeneous QoS resource manager with prediction 

      Nou Castell, Ramon; Torres Viñals, Jordi (IARIA, 2009)
      Conference report
      Open Access
      As long as computers continue to get more CPU processing power, data centers need to optimize their power usage. We can do this and maintain the same complexity level as before by using virtualized environments. We can put ...

    • HetFS: A heterogeneous file system for everyone 

      Koloventzos, Georgios; Nou Castell, Ramon; Miranda, Alberto; Cortés, Toni (Springer, 2017)
      Conference report
      Open Access
      Storage devices have been getting more and more diverse during the last decade. The advent of SSDs made it painfully clear that rotating devices, such as HDDs or magnetic tapes, were lacking in regards to response time. ...

    • Improving OpenStack Swift interaction with the I/O stack to enable software defined storage 

      Nou Castell, Ramon; Miranda, Alberto; Siquier, Marc; Cortés, Toni (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Conference report
      Open Access
      This paper analyses how OpenStack Swift, a distributed object storage service for a globally used middleware, interacts with the I/O subsystem through the Operating System. This interaction, which seems organised and clean ...

    • IOStack: Software-Defined Object Storage 

      Gracia-Tinedo, Raúl; García-López, Pedro; Sánchez-Artigas, Marc; Sampé, Josep; Moatti, Yosef; Rom, Eran; Naor, Dalit; Nou Castell, Ramon; Cortés, Toni; Oppermann, William; Michiardi, Pietro (Institute of Electrical and Electronics Engineers (IEEE), 2016-05-05)
      Article
      Open Access
      The complexity and scale of today’s cloud storage systems is growing fast. In response to these challenges, Software- Defined Storage (SDS) has recently become a prime candidate to simplify storage management in the ...

    • Multifaceted resource management for dealing with heterogeneous workloads in virtualized data centers 

      Goiri Presa, Íñigo; Fitó, Josep Oriol; Julià Masso, Ferran; Nou Castell, Ramon; Berral García, Josep Lluís; Guitart Fernández, Jordi; Torres Viñals, Jordi (IEEE Computer Society Publications, 2010)
      Conference lecture
      Open Access
      As long as virtualization has been introduced in data centers, it has been opening new chances for resource management. Now, it is not just used as a tool for consolidating underused nodes and save power, it also allows ...

    • Performance impacts with reliable parallel file systems at exascale level 

      Nou Castell, Ramon; Miranda, Alberto; Cortés, Toni (Springer, 2015)
      Conference report
      Restricted access - publisher's policy
      The introduction of Exascale storage into production systems will lead to an increase on the number of storage servers needed by parallel file systems. In this scenario, parallel file system designers should move from the ...

    • Simulating complex systems with a low-detail model 

      Nou Castell, Ramon; Guitart Fernández, Jordi; Beltran Querol, Vicenç; Carrera Pérez, David; Montero Mercadé, Lídia; Torres Viñals, Jordi; Ayguadé Parra, Eduard (2005-09)
      Conference report
      Open Access
      In this paper we show how modeling and simulating a complex system such as a web-server can help to evaluate di erent metrics and proposals to improve the performance without necessity of using a real system. Many times ...

    • Towards energy-aware scheduling in data centers using machine learning 

      Berral García, Josep Lluís; Goiri Presa, Íñigo; Nou Castell, Ramon; Julià, Ferran; Guitart Fernández, Jordi; Gavaldà Mestre, Ricard; Torres Viñals, Jordi (2010-04-15)
      Conference report
      Open Access
      As energy-related costs have become a major economical factor for IT infrastructures and data-centers, companies and the research community are being challenged to nd better and more efficient power-aware resource ...

    • Towards on-demand I/O forwarding in HPC platforms 

      Bez, Jean Luca; Zanon Boito, Francieli; Miranda Bueno, Alberto; Nou Castell, Ramon; Cortés, Toni; Navaux, Philippe O.A. (Institute of Electrical and Electronics Engineers (IEEE), 2020)
      Conference report
      Open Access
      I/O forwarding is an established and widely-adopted technique in HPC to reduce contention and improve I/O performance in the access to shared storage infrastructure. On such machines, this layer is often physically deployed ...

    • XtreemOS application execution management: a scalable approach 

      Nou Castell, Ramon; Giralt Celiméndiz, Jacobo; Corbalán González, Julita; Tejedor Saavedra, Enric; Fitó, Josep Oriol; Perez, Josep Maria; Cortés, Toni (IEEE Press. Institute of Electrical and Electronics Engineers, 2010)
      Conference report
      Open Access
      Designing a job management system for the Grid is a non-trivial task. While a complex middleware can give a lot of features, it often implies sacrificing performance. Such performance loss is especially noticeable for ...

    • XtreemOS-MD: Grid computing from mobile devices 

      Martínez, Álvaro; Prieto, Santiago; Gallego, Noé; Nou Castell, Ramon; Giralt, Jacobo; Cortés, Toni (2010-06)
      Conference report
      Open Access
      Grid and Cloud computing are well known topics, and currently one of the focus of many research and commercial projects. Nevertheless, the transparent access to Grid facilities from mobile devices (like PDAs or smartphones) ...

    • YOLO: Speeding Up VM and Docker Boot Time by Reducing I/O Operations 

      Nguyen, Thuy L.; Nou Castell, Ramon; Lebre, Adrien (Springer, 2019)
      Part of book or chapter of book
      Open Access
      Although this comes as a surprise, the time to boot a Docker-based container can last as long as a virtual machine in high consolidated cloud scenarios. Because this time is critical as boot duration defines how an application ...