Lluis Pamies-Juarez

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—Distributed storage systems need to store data redundantly in order to provide some fault-tolerance and guarantee system reliability. Different coding techniques have been proposed to provide the required redundancy more efficiently than traditional replication schemes. However, compared to replication, coding techniques are less efficient for repairing(More)
—Peer-to-peer (P2P) storage systems are strongly affected by churn —temporal and permanent peer failures. Because of this churn, the main requirement of such systems is to guarantee that stored objects can always be retrieved. This requirement is specially needed in two main situations: when users want to access the stored objects or when data maintenance(More)
Nowadays, data storage requirements from end-users are growing, demanding more capacity, more reliability and the capability to access information from anywhere. Cloud storage services meet this demand by providing transparent and reliable storage solutions. Most of these solutions are built on distributed infras-tructures that rely on data redundancy to(More)
—To achieve reliability in distributed storage systems, data has usually been replicated across different nodes. However the increasing volume of data to be stored has motivated the introduction of erasure codes, a storage efficient alternative to replication, particularly suited for archival in data centers, where old datasets (rarely accessed) can be(More)
Erasure codes are an integral part of many distributed storage systems aimed at Big Data, since they provide high fault-tolerance for low overheads. However, traditional erasure codes are inefficient on reading stored data in degraded environments (when nodes might be unavailable), and on replenishing lost data (vital for long term resilience).(More)
Peer-to-peer (P2P) storage is a promising technology to provide users with cheap and online persistence. However, due the instability of these infrastructures, P2P storage systems must introduce redundancy in order to guarantee a reliable storage service. Besides, they need data repair algorithms to maintain this redundancy in front of permanent node(More)
—Peer-to-peer (P2P) storage systems rely on data redundancy to obtain high levels of data availability. Among the existing data redundancy schemes, erasure coding is a widely adopted scheme in existing P2P storage systems. By properly tunning its parameters, erasure codes can minimize the required data redundancy, which reduces both the storage and the(More)