File migration in distributed computer systems

Porcar, Juan Burrut

doi:10.1016/0166-5316(83)90019-6

Cited by 10 publications

(4 citation statements)

References 19 publications

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“…The data were gathered as a series of daily scans of the disk, so they do not include files whose lifetimes were less than a day. In another study, Porcar analyzed dynamic trace data for files in an IBM batch environment [7]. He considered only shared files, which accounted for less than 10% of all the files accessed in his system.…”

Section: Previous Workmentioning

confidence: 98%

A trace-driven analysis of the UNIX 4.2 BSD file system

Ousterhout

Costa

Harrison

et al. 1985

Proceedings of the Tenth ACM Symposium on Operating Systems Principles

266

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We analyzed the UNIX 4.2 BSD file system by recording user-level activity in trace files and writing programs to analyze the traces. The tracer did not record individual read and write operations, yet still provided tight bounds on what information was accessed and when. The trace analysis shows that the average file system bandwidth needed per user is low (a few hundred bytes per second). Most of the files accessed are open only a short time and are accessed sequentially. Most new information is deleted or overwritten within a few minutes of its creation. We also wrote a simulator that uses the traces to predict the performance of caches for disk blocks. The moderate-sized caches used in UNIX reduce disk traffic for file blocks by about 50%, but larger caches (several megabytes) can eliminate 90% or more of all disk traffic. With those large caches, large block sizes (16 kbytes or more) result in the fewest disk accesses.

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Section: Previous Workmentioning

confidence: 98%

A trace-driven analysis of the UNIX 4.2 BSD file system

Ousterhout

Costa

Harrison

et al. 1985

Proceedings of the Tenth ACM Symposium on Operating Systems Principles

266

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“…The single data allocation problem has been shown to be intractable which means that as the problem size increases, problem search space increases exponentially [5,6,7,8,15] . Static data allocation implies that no change in data allocation as a function of time, while dynamic data allocation tends to relocate data as necessary [9,10,11] .…”

Section: Introductionmentioning

confidence: 99%

A Dynamic Object Fragmentation and Replication Algorithm In Distributed Database Systems

Sleit¹,

Almobaideen²,

Al-Areqi³

et al. 2007

American J. of Applied Sciences

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This paper proposes an enhancement for the ADRW algorithm to achieve dynamic fragmentation and object allocation in distributed databases. The algorithm adapts to the changing patterns of object requests with the objective to dynamically adjust the allocation schemes of objects in order to minimize the total servicing cost of all requests. Objects may be replicated or fragmented depending on patterns of reads and writes. Qualitative analysis was used to characterize the performance of the enhanced algorithm

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“…Empirical data from file systems has been used in many phases of the development of data storage systems. For example, such data has been used to study file caching 1,2 , placement 3 , and migration 4,5,6,7 . In this paper, we describe the design and implementation of a system called DFSTrace to collect long-term file reference data in a distributed workstation environment.…”

Section: Introductionmentioning

confidence: 99%

Long Term Distributed File Reference Tracing: Implementation and Experience

Mummert

Satyanarayanan

1996

Softw: Pract. Exper.

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DFSTruce is a system to collect and analyze long-term file reference data in a distributed UNIX workstation environment. The design of DFSTrace is unique in that it pays particular attention to the efficiency, extensibility and the logistics of long-term trace data collection in a distributed environment. The components of DFSTrace are a set of kernel hooks, a kernel buffer mechanism, a data extraction agent, a set of collection servers and post-processing tools.Our experience with DFSTrace has been highly positive. Tracing has been virtually unnoticeable, degrading performance 3-7 per cent, depending on the level of detail of tracing. We have collected file reference traces from approximately 30 workstations continuously for over two years. We have implemented a post-processing library to provide a convenient programmer interface to the traces and have created an on-line database of results from a suite of analysis programs to aid trace selection.Our data has been used for a wide variety of purposes, including file system studies, performance measurement and tuning and debugging. Extensions of DFSTrace have enabled its use in applications such as field reliability testing and determining disk geometry. This paper presents the design, implementation and evaluation of DFSTrace and associated tools and describes how they have been used. L. MUMMERT AND M. SATYANARAYANAN* UNIX is a registered trademark of UNIX Systems Laboratories, Inc. t AFS is a registered trademark of the Transarc Corporation. Client WorkstationsCollection Servers * We assume familiarity with the UNIX system call interface. For more information, see Section 2 of the UNIX Programmer's Manual.'6

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File migration in distributed computer systems

Cited by 10 publications

References 19 publications

A trace-driven analysis of the UNIX 4.2 BSD file system

A trace-driven analysis of the UNIX 4.2 BSD file system

A Dynamic Object Fragmentation and Replication Algorithm In Distributed Database Systems

Long Term Distributed File Reference Tracing: Implementation and Experience

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