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Journal ArticleDOI

Network attached storage architecture

01 Nov 2000-Communications of The ACM (ACM)-Vol. 43, Iss: 11, pp 37-45
TL;DR: How emerging technology may blur the network-centric distinction between NAS and SAN is about how the decreasing specialization of SAN protocols promises SAN-like devices on Ethernet network hardware.
Abstract: SAN with Fibre Channel network hardware that has a greater effect on a user’s purchasing decisions. This article is about how emerging technology may blur the network-centric distinction between NAS and SAN. For example, the decreasing specialization of SAN protocols promises SAN-like devices on Ethernet network hardware. Alternatively, the increasing specialization of NAS systems may embed much of the file system into storage devices. For users, it is increasingly worthwhile to investigate networked storage core and emerging technologies. Today, bits stored online on magnetic disks are so inexpensive that users are finding new, previously unaffordable, uses for storage. At Dataquest’s Storage2000 conference last June in Orlando, Fla., IBM reported that online disk storage is now significantly cheaper than paper or film, the dominant traditional information storage media. Not surprisingly, users are adding storage capacity at about 100% per year. Moreover, the rapid growth of e-commerce, with its huge global customer base and easy-to-use, online transactions, has introduced new market requirements, including bursty, unpredictable spurts in capacity, that demand vendors minimize the time from a user’s order to installation of new storage. In our increasingly Internet-dependent business and computing environment, network storage is the computer. NETWORK ATTACHED STORAGE ARCHITECTURE
Citations
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Journal ArticleDOI
TL;DR: Six key areas of streaming video are covered, including video compression, application-layer QoS control, continuous media distribution services, streaming servers, media synchronization mechanisms, and protocols for streaming media.
Abstract: Due to the explosive growth of the Internet and increasing demand for multimedia information on the Web, streaming video over the Internet has received tremendous attention from academia and industry. Transmission of real-time video typically has bandwidth, delay, and loss requirements. However, the current best-effort Internet does not offer any quality of service (QoS) guarantees to streaming video. Furthermore, for video multicast, it is difficult to achieve both efficiency and flexibility. Thus, Internet streaming video poses many challenges. In this article we cover six key areas of streaming video. Specifically, we cover video compression, application-layer QoS control, continuous media distribution services, streaming servers, media synchronization mechanisms, and protocols for streaming media. For each area, we address the particular issues and review major approaches and mechanisms. We also discuss the tradeoffs of the approaches and point out future research directions.

780 citations


Additional excerpts

  • ...18) [26]....

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Journal ArticleDOI
TL;DR: This survey aims to provide a thorough review of a wide range of in-memory data management and processing proposals and systems, including both data storage systems and data processing frameworks.
Abstract: Growing main memory capacity has fueled the development of in-memory big data management and processing. By eliminating disk I/O bottleneck, it is now possible to support interactive data analytics. However, in-memory systems are much more sensitive to other sources of overhead that do not matter in traditional I/O-bounded disk-based systems. Some issues such as fault-tolerance and consistency are also more challenging to handle in in-memory environment. We are witnessing a revolution in the design of database systems that exploits main memory as its data storage layer. Many of these researches have focused along several dimensions: modern CPU and memory hierarchy utilization, time/space efficiency, parallelism, and concurrency control. In this survey, we aim to provide a thorough review of a wide range of in-memory data management and processing proposals and systems, including both data storage systems and data processing frameworks. We also give a comprehensive presentation of important technology in memory management, and some key factors that need to be considered in order to achieve efficient in-memory data management and processing.

391 citations


Cites background from "Network attached storage architectu..."

  • ...Index Terms—Primary memory, DRAM, relational databases, distributed databases, query processing Ç...

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Patent
08 Nov 2005
TL;DR: In this article, a storage system consisting of a management server, a media management component, a plurality of storage media connected to the media management components, and a data source is described, and methods for protecting data in a tiered storage system are provided.
Abstract: Systems and methods for protecting data in a tiered storage system are provided. The storage system comprises a management server, a media management component connected to the management server, a plurality of storage media connected to the media management component, and a data source connected to the media management component. Source data is copied from a source to a buffer to produce intermediate data. The intermediate data is copied to both a first and second medium to produce a primary and auxiliary copy, respectively. An auxiliary copy may be made from another auxiliary copy. An auxiliary copy may also be made from a primary copy right before the primary copy is pruned.

340 citations

Patent
28 Jul 2003
TL;DR: In this paper, a multi-protocol storage appliance serves file and block protocol access to information stored on storage devices in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments.
Abstract: A multi-protocol storage appliance serves file and block protocol access to information stored on storage devices in an integrated manner for both network attached storage (NAS) and storage area network (SAN) deployments. A storage operating system of the appliance implements a file system (320) that cooperates with novel virtualization modules to provide a virtualization system (300) that “virtualizes” the storage space provided by the devices. The file system provides volume management capabilities for use in block-based access to the information stored on the devices. The virtualization system (300) allows the file system to logically organize the information as named file (324), directory (326) and virtual disk storage objects (322, 328) to thereby provide an integrated NAS and SAN appliance approach to storage by enabling file-based access to the files and directories while further enabling block-based access to the virtual disks.

336 citations

Patent
09 Sep 2003
TL;DR: In this paper, the authors propose a method for dynamically allocating control of a storage device, the method comprising receiving an access request from a first computer requesting access to a storage devices; directing, based upon the access request, a first storage controller computer to assume an inactive state with respect to control of the storage device; and then, based on the access requests, a second storage controller computers to assume a state of active control of storage devices.
Abstract: A method for dynamically allocating control of a storage device, the method comprising receiving an access request from a first computer requesting access to a storage device; directing, based upon the access request, a first storage controller computer to assume an inactive state with respect to control of the storage device; and directing, based upon the access request, a second storage controller computer to assume an active state with respect to control of the storage device.

331 citations

References
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Journal ArticleDOI
TL;DR: A reimplementation of the UNIX TM file system is described, which provides substantially higher throughput rates by using more flexible allocation policies that allow better locality of reference and can be adapted to a wide range of peripheral and processor characteristics.
Abstract: A reimplementation of the UNIX TM file system is described. The reimplementation provides substantially higher throughput rates by using more flexible allocation policies that allow better locality of reference and can be adapted to a wide range of peripheral and processor characteristics. The new file system clusters data that is sequentially accessed and provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long-needed enhancements to the programmers' interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.

906 citations

Proceedings Article
17 Jan 1994
TL;DR: WAFL (Write Anywhere File Layout) is described, which is a file system designed specifically to work in an NFS appliance, and how WAFL uses Snapshots to eliminate the need for file system consistency checking after an unclean shutdown.
Abstract: Network Appliance Corporation recently began shipping a new kind of network server called an NFS file server appliance, which is a dedicated server whose sole function is to provide NFS file service. The file system requirements for an NFS appliance are different from those for a general-purpose UNIX system, both because an NFS appliance must be optimized for network file access and because an appliance must be easy to use. This paper describes WAFL (Write Anywhere File Layout), which is a file system designed specifically to work in an NFS appliance. The primary focus is on the algorithms and data structures that WAFL uses to implement Snapshotst, which are read-only clones of the active file system. WAFL uses a copy-on-write technique to minimize the disk space that Snapshots consume. This paper also describes how WAFL uses Snapshots to eliminate the need for file system consistency checking after an unclean shutdown.

865 citations


"Network attached storage architectu..." refers background in this paper

  • ...Storage appliances are NAS systems intended to be especially simple to manage, ranging from Network Appliance’s terabyte servers to a disk drive with an Ethernet plug [5]....

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  • ..., chose a less-aggressive form of specialization, using general-purpose high-performance workstations and specialized (streamlined) operating and file systems [5]....

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Proceedings ArticleDOI
01 Sep 1996
TL;DR: The design, implementation, and performance of Petal is described, a system that attempts to approximate this ideal in practice through a novel combination of features.
Abstract: The ideal storage system is globally accessible, always available, provides unlimited performance and capacity for a large number of clients, and requires no management. This paper describes the design, implementation, and performance of Petal, a system that attempts to approximate this ideal in practice through a novel combination of features. Petal consists of a collection of network-connected servers that cooperatively manage a pool of physical disks. To a Petal client, this collection appears as a highly available block-level storage system that provides large abstract containers called virtual disks. A virtual disk is globally accessible to all Petal clients on the network. A client can create a virtual disk on demand to tap the entire capacity and performance of the underlying physical resources. Furthermore, additional resources, such as servers and disks, can be automatically incorporated into Petal.We have an initial Petal prototype consisting of four 225 MHz DEC 3000/700 workstations running Digital Unix and connected by a 155 Mbit/s ATM network. The prototype provides clients with virtual disks that tolerate and recover from disk, server, and network failures. Latency is comparable to a locally attached disk, and throughput scales with the number of servers. The prototype can achieve I/O rates of up to 3150 requests/sec and bandwidth up to 43.1 Mbytes/sec.

725 citations

Journal ArticleDOI
01 Oct 1998
TL;DR: Measurements of the prototype NASD system show that these services can be cost-effectively integrated into a next generation disk drive ASK, and show scaluble bandwidth for NASD-specialized filesystems.
Abstract: This paper describes the Network-Attached Secure Disk (NASD) storage architecture, prototype implementations oj NASD drives, array management for our architecture, and three, filesystems built on our prototype. NASD provides scalable storage bandwidth without the cost of servers used primarily, for transferring data from peripheral networks (e.g. SCSI) to client networks (e.g. ethernet). Increasing datuset sizes, new attachment technologies, the convergence of peripheral and interprocessor switched networks, and the increased availability of on-drive transistors motivate and enable this new architecture. NASD is based on four main principles: direct transfer to clients, secure interfaces via cryptographic support, asynchronous non-critical-path oversight, and variably-sized data objects. Measurements of our prototype system show that these services can be cost-effectively integrated into a next generation disk drive ASK. End-to-end measurements of our prototype drive andfilesysterns suggest that NASD cun support conventional distributed filesystems without performance degradation. More importantly, we show scaluble bandwidth for NASD-specialized filesystems. Using a parallel data mining application, NASD drives deliver u linear scaling of 6.2 MB/s per clientdrive pair, tested with up to eight pairs in our lab.

424 citations

01 Jun 1995
TL;DR: Zebra is a network file system that increases throughput by striping the file data across multiple servers by forming all the new data from each client into a single stream, which it then stripes using an approach similar to a log-structured file system.
Abstract: Zebra is a network file system that increases throughput by striping the file data across multiple servers. Rather than striping each file separately, Zebra forms all the new data from each client into a single stream, which it then stripes using an approach similar to a log-structured file system. This provides high performance for writes of small files as well as for reads and writes of large files. Zebra also writes parity information in each stripe in the style of RAID disk arrays; this increases storage costs slightly, but allows the system to continue operation while a single storage server is unavailable. A prototype implementation of Zebra, built in the Sprite operating system, provides 4–5 times the throughput of the standard Sprite file system or NFS for large files and a 15–300% improvement for writing small files.

352 citations


"Network attached storage architectu..." refers background in this paper

  • ...The most common trusts client operating systems to request and cache file system metadata [4]....

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