parallel read/write performance

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LDPLFS : Improving I/O performance without application modification

LDPLFS : Improving I/O performance without application modification

One recent project of note is the Parallel Log-structured File System (PLFS) which is being actively developed by EMC Corporation, the Los Alamos National Laboratory (LANL) and their academic and industrial partners [1]. To date, PLFS has been reported to yield large gains in both application read and write performance through the utilisation of two well known principles for improving parallel file system performance: (i) through the use of a log-structured file system – where write operations are performed sequentially to the disk regardless of intended file offsets (keeping the offsets in an index structure instead); and (ii) through the use of file partitioning – where a write to a single file is instead transparently transposed into a write to many files, increasing the number of available file streams.
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LDPLFS : improving I/O performance without application modification

LDPLFS : improving I/O performance without application modification

One recent project of note is the Parallel Log-structured File System (PLFS) which is being actively developed by EMC Corporation, the Los Alamos National Laboratory (LANL) and their academic and industrial partners [1]. To date, PLFS has been reported to yield large gains in both application read and write performance through the utilisation of two well known principles for improving parallel file system performance: (i) through the use of a log-structured file system – where write operations are performed sequentially to the disk regardless of intended file offsets (keeping the offsets in an index structure instead); and (ii) through the use of file partitioning – where a write to a single file is instead transparently transposed into a write to many files, increasing the number of available file streams.
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Hypervisor-based Background Encryption

Hypervisor-based Background Encryption

Background Encryption in Hypervisor • Guest performance • IO intermixture • Read/write timing Hypervisor Hardware OS IO IO. Hypervisor reads/encrypts/writes disk in parallel with gues[r]

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Evaluating I/O Scheduling in Virtual Machines Based on Application Load

Evaluating I/O Scheduling in Virtual Machines Based on Application Load

experimental data show that in virtual environment, the delay performance of the VM virtual disk is very different from that of the physical hard disk. When adjusting the VM's I/O performance, it is necessary to consider VM, VMM and hardware factors. His experiments adjusted anticipatory and cfq scheduling algorithms in VM, and figured out optimization requirements of scheduling in VMM. The VMM proposed in the first two solutions refers to Dom0 in Xen architecture. However, when running multiple virtual domains, the impact of Xen credit Scheduler’s VM scheduling policy on VM I/O performance cannot be ignored. Diego et.al [4] studied the relationship between hypervisor scheduling and I/O performance. They selected a variety of computing-intensive, bandwidth-intensive and delay-sensitive combinations to run simultaneously in multiple virtual domains. After adjusting 11 scheduling parameters in VMM, they observed the changes in bandwidth and response time, and came to a conclusion that Xen Credit scheduler has a major impact on application I/O performance.
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6028-1_TDC-4100_Series_Maintenance_Oct1991.pdf

6028-1_TDC-4100_Series_Maintenance_Oct1991.pdf

The Write Current, Write Symmetry, Read Gain, Read Channel Pulse Slimming and the Read Clock Center Frequency will be automatically adjusted for all tape and format combinations. T[r]

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63046 001 Series 5099EQ 5125EQ 5150EQ QIC 02 Cartridge Drive OEM Manual 1987 pdf

63046 001 Series 5099EQ 5125EQ 5150EQ QIC 02 Cartridge Drive OEM Manual 1987 pdf

No Cartridge Device Fault Rag Write Protected End Of Media Read or Write Abort Read Error, Bad Block Transfer Read Error, No Data Read Error, No Data & EOM Read A File Mark Illegal Comma[r]

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Read/Write Devices based on the HITAG Read/Write IC HTRC110

Read/Write Devices based on the HITAG Read/Write IC HTRC110

The demodulator of the HTRC110 contains several analog and switched capacitor filters. For generating the threshold for digitizing the analog demodulator output signal a sophisticated circuitry has been implemented. All these function blocks need some time for settling after changing operation conditions e.g. power on, reactivating after power down modes, changing the sampling time or sending WRITE-pulses. This settling has to be com- pletely finished before the transponder sends the first relevant data bit. The system has to actively be settled completely to allow demodulation of the data. Also other transponders require a defined maximum settling time after power-up or after writing data. Therefore special circuitries have been implemented into the HTRC110 to accelerate settling. This fast settling is activated by setting and resetting special bits in the configuration page 2. The maximum settling time can be optimized by adapting the bit combination and delays between the com- mands. Final results will be published in future.
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VisualBasic Reference Guide

VisualBasic Reference Guide

IncludeCopyright Boolean read/write include copyright for thumbnail ( default: false ) IncludeCredits Boolean read/write include credits for thumbnail ( default: false ) IncludeFilename Boolean read/write include fi le name for thumbnail ( default: false ) IncludeTitle Boolean read/write include title for thumbnail ( default: false )

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A New Approach for Detecting Memory Errors in JPEG2000 Standard

A New Approach for Detecting Memory Errors in JPEG2000 Standard

JPEG and JPEG2000 are the most widely used image compression standards in compensating memory errors. JPEG has slightly less compression performance than JPEG2000 [1]. JPEG is based on DCT whereas; JPEG2000 is based on DWT where each sub-band is divided into rectangular blocks, called code-blocks. DWT provides less computational complexity which can compensate memory errors drastically [2]. JPEG2000 outperforms JPEG in terms of compression ratio. JPEG2000 algorithm produces excellent results, better image quality as compared to JPEG [3].Set partitioning in hierarchical tress (SPHIT) is also most widely used compression algorithm. It can also be combined with DCT and DWT for higher compression efficiency. It provides good image quality but cannot compensate the memory errors [4]. Block truncation coding (BTC) algorithm were also used for colour image compression which also provides good image quality cannot reduce memory errors [5]. Hence, JPEG2000 will be effective to operate SRAM under low-power mode which is a DWT based image compression standard can also compensate memory errors [6]. An effective way of reducing memory power is voltage scaling. About 35% powers saving is possible in the following JPEG2000 when memory operates at Scaled voltages [7]. This paper explains error control coding schemes such as adaptive Error control coding, single error correction double error detection (SECDED). The errors such as random errors and burst errors are replaced by these codes. These schemes are most suitable for SRAM [8].
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Tailor-made Concurrency Control - distributed transactions as a case

Tailor-made Concurrency Control - distributed transactions as a case

Further, the binary relations WR-RW-WW Y (H) and WR-RW-WW y (H) contain the sets of ordered pairs of transactions corresponding to the write-read, read-write and write-write conflicts in[r]

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Teaching bodies to read and write. A technosomatic perspective

Teaching bodies to read and write. A technosomatic perspective

ABSTRACT. In this article Joris Vlieghe defends the view that technologies of reading and writing are more than merely instruments that support education, but that they themselves decide on what education is all about and that they form subjectivity in substantial ways. Expanding on insights taken from Media Theory, Vlieghe uses the work of Stiegler in order to develop a “technosomatic” account of literacy initiation, i.e. a perspective that zooms in on the physical dimensions of how to operate writing and reading technologies. He argues that that the bodily gestures and disciplines that constitute (elementary) literacy give rise to a particular space of experience, which comes down to a heavily embodied, first-hand sense of what it means to be able to produce script. Vlieghe argues that the advent of digital writing and reading technologies implies a fundamental shift in this sense of ability, and that in order to understand digital literacy we need to take into account the technosomatic aspects of learning to read and write with digital media (a dimension which is absent from the way in which the New Literacy movement
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US4476503.pdf

US4476503.pdf

A method for recognizing an edge of a magnetic tape, comprising the steps of: providing a read and write unit having a write head and a read head; moving the. tape from the write head[r]

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Icom FD360 CF360 Maintenance Manual Nov1975 pdf

Icom FD360 CF360 Maintenance Manual Nov1975 pdf

Examine Status Read Write Read eRe Seek Clear Error Flags Seek Track 0 Write with DDAM* Load -Track Address Load Unit/Sector.. Load Write Buffer Shift Read Buffer.[r]

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Improving efficiency of persistent storage access in embedded Linux

Improving efficiency of persistent storage access in embedded Linux

To investigate a simpler interface to storage from Linux that bypasses file systems and the block layer, a driver was created that presents an NVMe SSD to user-space applications as a basic character device. Using a character device has the advantage of conforming to the standard model of device nodes being accessible through the VFS, while removing complex block layer features such as the I/O scheduler, request queueing mechanisms, page cache, and asynchronous requests. At a high level, the CharIO kernel module acts as a wrapper around a modified version of the standard Linux NVMe device driver, creating a /dev/chardiskX character device node instead of a /dev/nvmeXnX block device node when an SSD is attached. This device node can then be accessed from user-space applications, supporting the standard open, close, read, write and seek system calls, and translating these into commands sent directly to the underlying storage device. This is shown against the standard Linux storage stack in Figure 2. For efficiency during a read or write, all data is directly transferred by the storage hardware to or from buffers within the user-space application, similar to how ‘direct I/O’ func- tions. This requires transfers to be aligned to the block structure of the underlying storage device, for example, a transfer size must be a multiple of 4096 bytes if that is the block size used. Each transfer is completed atomically and sequentially, with system calls blocking as data is transferred, after which control is returned to the calling application. A. Low-level Operation
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Children Learn to Read and Write Chinese Analytically

Children Learn to Read and Write Chinese Analytically

The functions of stroke-patterns are indicated by their positions within a character. If a stroke-pattern constitutes a semantic radical, it has a fixed position in the pattern in any ch[r]

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Implementation of Multi-channel FIFO in One BlockRAM with Parallel Access to One Port

Implementation of Multi-channel FIFO in One BlockRAM with Parallel Access to One Port

With experience in previous FPGA projects, we have realized the design of PIPOFIFO of multi-channel FIFO and successfully applied it to data buffer of bus transceiver of Multifunction Vehicle Bus (MVB) and data cache of large LED display screen. The structure of PIPOFIFO is depicted in Figure 1. To realize the PIPOFIFO, a simple DPRAM is instantiated from a BlockRAM at first, its memory space is divided into multiple parts according to the number of the channels of PIPOFIFO (4 channels in Figure 1). The input data of all channels, from din_0 to din_3, are written in simultaneously under the uniform signal wr_enx, and the output data of all channels, from dout_0 to dout_3, are read out simultaneously under the uniform signal rd_enx. The label logics of all the channels are the same, so one set of them is enough. Actually the PIOPFIFO can be simply viewed as a binding of multiple normal FIFOs and act as one normal FIFO.
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Parallel processes : getting it write?

Parallel processes : getting it write?

analysis we employ aspects of a reflective methodology to explore our experience of straddling the tensions between the child at the centre and the wider context, as played out in the writing of an applied text in the era of externally evaluated and measured scholarship. While we assume other writers will have had at least some similar reflections, t h i s p a p e r a d d s t o t h e b o d y o f e x i s t i n g l i t e r a t u r e b y exposing some of the ‘backstage’ (Goffman, 1956) processes and considerations as a means of opening up dialogue and shared insight related to these tensions. Moreover, we offer them not only to demonstrate some of the parallel processes between direct practice and practice-related academic writing, but to argue that by illuminating these processes, their deleterious effects can be mitigated and their enhancing potential harnessed in order to improve their impact.
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Benchmarking Cloud Serving Systems with YCSB

Benchmarking Cloud Serving Systems with YCSB

While the use of MapReduce systems (such as Hadoop) for large scale data analysis has been widely recognized and studied, we have recently seen an explosion in the number of systems developed for cloud data serving. These newer systems address “cloud OLTP” applications, though they typically do not support ACID transactions. Examples of systems proposed for cloud serving use include BigTable, PNUTS, Cassandra, HBase, Azure, CouchDB, SimpleDB, Voldemort, and many others. Further, they are being ap- plied to a diverse range of applications that differ consider- ably from traditional (e.g., TPC-C like) serving workloads. The number of emerging cloud serving systems and the wide range of proposed applications, coupled with a lack of apples- to-apples performance comparisons, makes it difficult to un- derstand the tradeoffs between systems and the workloads for which they are suited. We present the Yahoo! Cloud Serving Benchmark (YCSB) framework, with the goal of fa- cilitating performance comparisons of the new generation of cloud data serving systems. We define a core set of benchmarks and report results for four widely used systems: Cassandra, HBase, Yahoo!’s PNUTS, and a simple sharded MySQL implementation. We also hope to foster the devel- opment of additional cloud benchmark suites that represent other classes of applications by making our benchmark tool available via open source. In this regard, a key feature of the YCSB framework/tool is that it is extensible—it supports easy definition of new workloads, in addition to making it easy to benchmark new systems.
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Title : Low Power Circuit Design for SRAM Using Hetro Junction Tunneling TransistorAuthor (s) :Suganya.S, A.Nandhini, Sindhumathi.K

Title : Low Power Circuit Design for SRAM Using Hetro Junction Tunneling TransistorAuthor (s) :Suganya.S, A.Nandhini, Sindhumathi.K

Abstract: The aim of this project is to design the 6T SRAM using SRAM and HETT. This project is carried out to investigate the performance and the characteristics of the SRAM. The 6T SRAM cell is selected cell to be design in this project due to higher performance of the cell compared with the other type of cell. The objectives of this study are to design the SRAM cell by using the TSPICE software in two operations in the 6T SRAM cells which are in the write and read operation. The operation time of each operation is observed and compared. The complete time taken for the read operation is higher than write operation. Then power dissipation in the write and read operation are calculated and discussed for various type of SRAMs during read and write operation.Finally 6T SRAM,7TSRAM and Schmitt trigger based 6T SRAM and 6T SRAM using adiabatic logic are designed and results are compared with its 4*4 SRAM array logic.
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E-Governance: A Journey of Challenges, Failures and Success in India

E-Governance: A Journey of Challenges, Failures and Success in India

An ability to read and write along with proper understanding in any language is defined as literacy and an individual who are able to read and write with appropriate understanding is te[r]

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