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Plutus is a cryptographic storage system that enables secure file sharing without placing much trust on the file servers. In particular, it makes novel use of cryptographic primitives to protect and share files. Plutus features highly scalable key management while allowing individual users to retain direct control over who gets access to their files. We(More)
There are a variety of ways to ensure the security of data and the integrity of data transfer , depending on the set of anticipated attacks, the level of paranoia on the part of the data owners, and the level of inconvenience users are willing to tolerate. Current storage systems secure data either by encrypting data on the wire, or by encrypting data on(More)
Despite the importance of storage in enterprise computer systems, there are few adequate tools to design and configure a storage system to meet application data requirements efficiently. Storage system design involves choosing the disk arrays to use, setting the configuration options on those arrays, and determining an efficient mapping of application data(More)
In benchmarking I/O systems, it is important to generate, accurately, the I/O access pattern that one is intending to generate. However, timing accuracy (issuing I/Os at the desired time) at high I/O rates is difficult to achieve on stock operating systems. We currently lack tools to easily and accurately generate complex I/O workloads on modern storage(More)
—We address the problem of prefetching and caching in a parallel I/O system and present a new algorithm for parallel disk scheduling. Traditional buffer management algorithms that minimize the number of block misses are substantially suboptimal in a parallel I/O system where multiple I/Os can proceed simultaneously. We show that in the offline case, where a(More)
We provide a competitive analysis framework for online prefetching and buffer management algorithms in parallel IrO systems, using a read-once model of block references. This has widespread applicability to key IrO-bound applications such as external merging and concurrent playback of multiple video streams. Two realistic lookahead models, global lookahead(More)
An optimal prefetching and I/O scheduling algorithm L-OPT, for parallel I/O systems, using a read-once model of block references is presented. The algorithm uses knowledge of the next Ä references, Ä-block lookahead, to create a minimal-length I/O schedule. We show that the competitive ratio of L-OPT is ¢´Ô Šĵ, Ä Å , which matches the lower bound of any(More)
The cost of large storage systems is dominated by management costs. Typically, skilled administrators configure storage manually using rules of thumb. However, designing a storage system for a given workload is a difficult task, because there are millions of possible configurations and mappings of data, and because storage system behavior is complex.(More)