27,261 research outputs found

    Procedures and tools for acquisition and analysis of volatile memory on android smartphones

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    Mobile phone forensics have become more prominent since mobile phones have become ubiquitous both for personal and business practice. Android smartphones show tremendous growth in the global market share. Many researchers and works show the procedures and techniques for the acquisition and analysis the non-volatile memory inmobile phones. On the other hand, the physical memory (RAM) on the smartphone might retain incriminating evidence that could be acquired and analysed by the examiner. This study reveals the proper procedure for acquiring the volatile memory inthe Android smartphone and discusses the use of Linux Memory Extraction (LiME) for dumping the volatile memory. The study also discusses the analysis process of the memory image with Volatility 2.3, especially how the application shows its capability analysis. Despite its advancement there are two major concerns for both applications. First, the examiners have to gain root privileges before executing LiME. Second, both applications have no generic solution or approach. On the other hand, currently there is no other tool or option that might give the same result as LiME and Volatility 2.3

    Improving the Performance and Endurance of Persistent Memory with Loose-Ordering Consistency

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    Persistent memory provides high-performance data persistence at main memory. Memory writes need to be performed in strict order to satisfy storage consistency requirements and enable correct recovery from system crashes. Unfortunately, adhering to such a strict order significantly degrades system performance and persistent memory endurance. This paper introduces a new mechanism, Loose-Ordering Consistency (LOC), that satisfies the ordering requirements at significantly lower performance and endurance loss. LOC consists of two key techniques. First, Eager Commit eliminates the need to perform a persistent commit record write within a transaction. We do so by ensuring that we can determine the status of all committed transactions during recovery by storing necessary metadata information statically with blocks of data written to memory. Second, Speculative Persistence relaxes the write ordering between transactions by allowing writes to be speculatively written to persistent memory. A speculative write is made visible to software only after its associated transaction commits. To enable this, our mechanism supports the tracking of committed transaction ID and multi-versioning in the CPU cache. Our evaluations show that LOC reduces the average performance overhead of memory persistence from 66.9% to 34.9% and the memory write traffic overhead from 17.1% to 3.4% on a variety of workloads.Comment: This paper has been accepted by IEEE Transactions on Parallel and Distributed System

    Instant restore after a media failure

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    Media failures usually leave database systems unavailable for several hours until recovery is complete, especially in applications with large devices and high transaction volume. Previous work introduced a technique called single-pass restore, which increases restore bandwidth and thus substantially decreases time to repair. Instant restore goes further as it permits read/write access to any data on a device undergoing restore--even data not yet restored--by restoring individual data segments on demand. Thus, the restore process is guided primarily by the needs of applications, and the observed mean time to repair is effectively reduced from several hours to a few seconds. This paper presents an implementation and evaluation of instant restore. The technique is incrementally implemented on a system starting with the traditional ARIES design for logging and recovery. Experiments show that the transaction latency perceived after a media failure can be cut down to less than a second and that the overhead imposed by the technique on normal processing is minimal. The net effect is that a few "nines" of availability are added to the system using simple and low-overhead software techniques
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