The Experts below are selected from a list of 15375 Experts worldwide ranked by ideXlab platform

Jerry Hamann - One of the best experts on this subject based on the ideXlab platform.

  • microsoft exchange implementation on a distributed storage area network
    International Journal of Computers and Applications, 2008
    Co-Authors: Nagapramod Mandagere, Jerry Hamann, Suresh Muknahallipatna, Howard Johnson
    Abstract:

    AbstractThe ever-increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. Direct attached storage (DAS) architecture, also known as server-centric architecture, is being replaced by the storage area network (SAN), leading to storage-centric architecture. In SAN storage devices exist completely independent of any computer (servers in particular). Multiple servers can access the same storage device without involvement of other servers. Recently, companies have been able to implement storage integration/sharing, remote backup/restoral, near-real-time disk mirroring/replication, and the like, using a new SAN architecture known as distributed storage area network (DSAN). The DSAN is multiple SANs interconnected using existing Internet Protocol (IP) networks to distribute storage over wide geographical areas. Even though DSANs provide additional capabilities to a SAN, the end-to-end latency (ETEL) due to large physical cable lengths (IP networks) imposes limitations...

  • fibre channel switch modeling at fibre channel 2 level for large fabric storage area network simulations using omnet preliminary results
    Local Computer Networks, 2007
    Co-Authors: Suresh Muknahallipatna, Jerry Hamann
    Abstract:

    Medium sized storage area networks using fibre channel have been a common implementation for data storage in enterprise data centers. The ever increasing demand for large storage pools has paved to the idea of implementing large distributed storage area networks also known as large fabrics. The large fabrics seem to experience fabric scaling and fabric stability issues. These scaling and stability issues are related to the performance of various fabric servers of fabric services, such as fabric controller, fabric login, directory, etc., which are part of the fibre channel-2 level of the fibre channel protocol. To determine the extent of scaling and stability issues of a large fabric an adequate tool is required. The tool could be an analytical model, a hardware simulator, or a discrete event software simulator. The discrete event software simulator provides a number of benefits over the analytical model and hardware simulator. In this paper, the modeling of a fibre channel switch using the OMNeT++ discrete event simulator and simulation of large fabric are presented. As a first step, only the fibre channel-2 level of the fibre channel switch is modeled since it is the layer containing various fabric services dealing with fabric building and managing. In this paper, the process of building a fabric and managing and how it is implemented in the simulator are discussed. Also, a preliminary analysis of the results in comparison to the test bed traffic is presented showing the accuracy and representation of an actual large fabric by the simulator.

  • the effect of end to end latency in a distributed storage area network on microsoft exchange server 2003 performance part i
    Local Computer Networks, 2004
    Co-Authors: Suresh Muknahallipatna, Nagapramod Mandagere, P. Patil, Jerry Hamann
    Abstract:

    The ever increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. The direct attached storage (DAS) model is being replaced by storage area networks (SANs). SANs provide the capability to distribute the storage across multiple servers leading to decentralized and externalized storage. Recently, the accessibility of SANs to small companies has been improved by using existing IP networks to distribute storage over long geographical distances, leading to the distributed storage area network (DSAN). Although DSANs have provided additional capabilities to SANs, they have created a new set of problems for enterprise class applications, like Microsoft Exchange Server 2003, with increasing end to end latency (ETEL), due to large physical cable lengths. We present an attempt to analyze the effect of ETEL in DSAN on the performance of Microsoft Exchange Server 2003 by monitoring the Exchange behavior using LoadSim 2003 benchmark.

  • LCN - The effect of end to end latency in a distributed storage area network on Microsoft Exchange Server 2003 performance - Part I
    29th Annual IEEE International Conference on Local Computer Networks, 2004
    Co-Authors: Suresh Muknahallipatna, Nagapramod Mandagere, P. Patil, Jerry Hamann
    Abstract:

    The ever increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. The direct attached storage (DAS) model is being replaced by storage area networks (SANs). SANs provide the capability to distribute the storage across multiple servers leading to decentralized and externalized storage. Recently, the accessibility of SANs to small companies has been improved by using existing IP networks to distribute storage over long geographical distances, leading to the distributed storage area network (DSAN). Although DSANs have provided additional capabilities to SANs, they have created a new set of problems for enterprise class applications, like Microsoft Exchange Server 2003, with increasing end to end latency (ETEL), due to large physical cable lengths. We present an attempt to analyze the effect of ETEL in DSAN on the performance of Microsoft Exchange Server 2003 by monitoring the Exchange behavior using LoadSim 2003 benchmark.

Suresh Muknahallipatna - One of the best experts on this subject based on the ideXlab platform.

  • Fibre Channel Switch Modeling at Fibre Channel-2 Level for Large Fabric storage area network Simulations using OMNeT++
    GSTF Journal on computing, 2014
    Co-Authors: Suresh Muknahallipatna, Joseph Miles, Howard Johnson
    Abstract:

    Abstract—Typically, in the current enterprise data centers dedicated fabrics or networks are implemented to meet their LAN, Inter-Processor communication and storage traffic requirements. The storage traffic requirements of a group of servers are met through multiple storage area networks based on fibre channel, which has become the standard connection type. Typically, this fibre channel storage area networks are small (maximum of 32 switches/directors in a single fabric) and do not experience any scaling, stability and other performance issues. The advent of I/O consolidation in enterprise data centers for multiple traffic types to converge on to a single fabric or network (typically Ethernet platform) to reduce hardware, energy and management costs has also the potential to allow implementation of large storage area networks based on the fibre channel standards. Large storage area networks are being planned with more than two hundred switches/directors in a single fabric or network in addition to servers and storages connected to the fabric on Ethernet platforms. Even though these large storage area networks are envisioned to operate on Ethernet platform, they still have to satisfy the stringent operating and performance requirement set forth by the fibre channel standards. The two important issues of concern with large storage area networks are scaling and stability. The scaling and stability issues are dependent on the interactions and performance capabilities of various fabric servers located on each switch/director in the fabric in order to provide fabric services. In order to determine the extent of scaling and stability issues of a large fabric first the detailed models of the switch/director addressing the operations of the individual fabric servers are required. Next, the interactions of the switches/directors using the detailed models are to be simulated to study the scaling and stability issues. In this paper, the detailed modeling of the fibre channel switch and the fabric servers using the OMNeT++ discrete event simulator is presented first. Detailed models are developed addressing the behavior of the switch at the level-2 of the fibre channel protocol since this layer addresses the requirements and operations of various mandatory fabric services like fabric build, directory, login, nameserver, management, etc. Next, using the OMNET++ discrete event simulator large fabrics are simulated. The results from the simulation are compared against the test bed traffic and the accuracy is demonstrated. Also, results and analysis of multiple simulations with increasing fabric size are presented.

  • microsoft exchange implementation on a distributed storage area network
    International Journal of Computers and Applications, 2008
    Co-Authors: Nagapramod Mandagere, Jerry Hamann, Suresh Muknahallipatna, Howard Johnson
    Abstract:

    AbstractThe ever-increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. Direct attached storage (DAS) architecture, also known as server-centric architecture, is being replaced by the storage area network (SAN), leading to storage-centric architecture. In SAN storage devices exist completely independent of any computer (servers in particular). Multiple servers can access the same storage device without involvement of other servers. Recently, companies have been able to implement storage integration/sharing, remote backup/restoral, near-real-time disk mirroring/replication, and the like, using a new SAN architecture known as distributed storage area network (DSAN). The DSAN is multiple SANs interconnected using existing Internet Protocol (IP) networks to distribute storage over wide geographical areas. Even though DSANs provide additional capabilities to a SAN, the end-to-end latency (ETEL) due to large physical cable lengths (IP networks) imposes limitations...

  • fibre channel switch modeling at fibre channel 2 level for large fabric storage area network simulations using omnet preliminary results
    Local Computer Networks, 2007
    Co-Authors: Suresh Muknahallipatna, Jerry Hamann
    Abstract:

    Medium sized storage area networks using fibre channel have been a common implementation for data storage in enterprise data centers. The ever increasing demand for large storage pools has paved to the idea of implementing large distributed storage area networks also known as large fabrics. The large fabrics seem to experience fabric scaling and fabric stability issues. These scaling and stability issues are related to the performance of various fabric servers of fabric services, such as fabric controller, fabric login, directory, etc., which are part of the fibre channel-2 level of the fibre channel protocol. To determine the extent of scaling and stability issues of a large fabric an adequate tool is required. The tool could be an analytical model, a hardware simulator, or a discrete event software simulator. The discrete event software simulator provides a number of benefits over the analytical model and hardware simulator. In this paper, the modeling of a fibre channel switch using the OMNeT++ discrete event simulator and simulation of large fabric are presented. As a first step, only the fibre channel-2 level of the fibre channel switch is modeled since it is the layer containing various fabric services dealing with fabric building and managing. In this paper, the process of building a fabric and managing and how it is implemented in the simulator are discussed. Also, a preliminary analysis of the results in comparison to the test bed traffic is presented showing the accuracy and representation of an actual large fabric by the simulator.

  • LCN - Fibre Channel based storage area network Modeling using OPNET for Large Fabric Simulations: Preliminary Work
    32nd IEEE Conference on Local Computer Networks (LCN 2007), 2007
    Co-Authors: J. Staley, Suresh Muknahallipatna, Howard Johnson
    Abstract:

    Fibre channel based storage area networks have been a common implementation for data storage in enterprise data centers. As the size of the storage area network tends to grow along with geographical distribution leading to distributed storage area network, also known as large fabric, the network seems to exhibit scaling and stability issues. The scaling and stability issues seem to stem from the construction, route discovery, and management process of the network which are fibre channel-2 level traffic more than the actual I/O data transmission process. To determine the scaling and stability issues of a large fabric, an adequate tool is required. The tool is usually a discrete event simulator since an analytical or hardware simulator tool would not be able to handle the large size of the storage area network and model in detail. In this paper, the preliminary work on modeling and simulations of a fibre channel based storage area network using OPNET as a discrete event simulator are presented. As a preliminary step, the fibre channel host bus adapter and its interactions with the fabric login server of a fibre channel switch during the fabric login process is modeled at the fibre channel-2 level and preliminary simulations are performed.

  • the effect of end to end latency in a distributed storage area network on microsoft exchange server 2003 performance part i
    Local Computer Networks, 2004
    Co-Authors: Suresh Muknahallipatna, Nagapramod Mandagere, P. Patil, Jerry Hamann
    Abstract:

    The ever increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. The direct attached storage (DAS) model is being replaced by storage area networks (SANs). SANs provide the capability to distribute the storage across multiple servers leading to decentralized and externalized storage. Recently, the accessibility of SANs to small companies has been improved by using existing IP networks to distribute storage over long geographical distances, leading to the distributed storage area network (DSAN). Although DSANs have provided additional capabilities to SANs, they have created a new set of problems for enterprise class applications, like Microsoft Exchange Server 2003, with increasing end to end latency (ETEL), due to large physical cable lengths. We present an attempt to analyze the effect of ETEL in DSAN on the performance of Microsoft Exchange Server 2003 by monitoring the Exchange behavior using LoadSim 2003 benchmark.

Fan Zhang - One of the best experts on this subject based on the ideXlab platform.

  • implementation of a 6 times 6 free space optical fiber ribbon switch for storage area networks
    Journal of Lightwave Technology, 2012
    Co-Authors: Hsihsir Chou, Fan Zhang, Timothy D. Wilkinson, N Collings, W A Crossland
    Abstract:

    A shutter-based free-space optical switching architecture capable of multicast transmission functionality has been proposed as a promising switching technology for storage area network applications. The main idea behind this type of switching architecture is that the system performance can be enhanced with a new electro-optical material, used for the shutters to increase switching speed. It can be distinguished from previous shutter-based optical switches which have been based on single channel to single channel switching, as we present a reconfigurable design of a 6 × 6 72-channel shutter-based optical switching core based on multimode fiber ribbon to multimode fiber ribbon switching. The design and implementation of a prototype 6 × 6 72-channel multi-mode fiber ribbon switch demonstrator utilizing a submicrosecond PLZT-based spatial light modulator as a shutter is reported. The light loss, crosstalk, and data switching characteristics of the implemented fiber ribbon switch from the evaluation tests were measured and are presented.

  • Free-space optical switching core for storage area network
    Optical Transmission Switching and Subsystems II, 2005
    Co-Authors: Fan Zhang, Neil Collings, William A. Crossland, Timothy D. Wilkinson, Mark Fan, Mohammad R. Taghizadeh, Andrew J. Waddie
    Abstract:

    storage area network (SAN) has gradually developed as the demand for storage capacity and fast access has increased. The traditional way of attaching storage directly to the servers over a SCSI bus has limited scalability. Several drawbacks and limitations have turned up. Switched Fibre Channel SAN resolves all of these issues. In this paper, the architecture of the switch fabric for the SAN is discussed. The complete design of the free-space optical switching core based on the diffractive element and the PLZT shutter is proposed.

  • Reconfigurable free-space optical cores for storage area networks
    IEEE Communications Magazine, 2005
    Co-Authors: Timothy D. Wilkinson, Neil Collings, B. Crossland, Fan Zhang
    Abstract:

    The role of the optical storage area network is becoming increasingly important in computer network architectures, with the amount of information being presented and requested on the Internet ever increasing. One of the key questions is what is the role of, and how do we control, an optical switch core within a SAN to optimize its performance. In this article we review two potential optical switch technologies and assess their performance as a SAN optical switch core.

Howard Johnson - One of the best experts on this subject based on the ideXlab platform.

  • Fibre Channel Switch Modeling at Fibre Channel-2 Level for Large Fabric storage area network Simulations using OMNeT++
    GSTF Journal on computing, 2014
    Co-Authors: Suresh Muknahallipatna, Joseph Miles, Howard Johnson
    Abstract:

    Abstract—Typically, in the current enterprise data centers dedicated fabrics or networks are implemented to meet their LAN, Inter-Processor communication and storage traffic requirements. The storage traffic requirements of a group of servers are met through multiple storage area networks based on fibre channel, which has become the standard connection type. Typically, this fibre channel storage area networks are small (maximum of 32 switches/directors in a single fabric) and do not experience any scaling, stability and other performance issues. The advent of I/O consolidation in enterprise data centers for multiple traffic types to converge on to a single fabric or network (typically Ethernet platform) to reduce hardware, energy and management costs has also the potential to allow implementation of large storage area networks based on the fibre channel standards. Large storage area networks are being planned with more than two hundred switches/directors in a single fabric or network in addition to servers and storages connected to the fabric on Ethernet platforms. Even though these large storage area networks are envisioned to operate on Ethernet platform, they still have to satisfy the stringent operating and performance requirement set forth by the fibre channel standards. The two important issues of concern with large storage area networks are scaling and stability. The scaling and stability issues are dependent on the interactions and performance capabilities of various fabric servers located on each switch/director in the fabric in order to provide fabric services. In order to determine the extent of scaling and stability issues of a large fabric first the detailed models of the switch/director addressing the operations of the individual fabric servers are required. Next, the interactions of the switches/directors using the detailed models are to be simulated to study the scaling and stability issues. In this paper, the detailed modeling of the fibre channel switch and the fabric servers using the OMNeT++ discrete event simulator is presented first. Detailed models are developed addressing the behavior of the switch at the level-2 of the fibre channel protocol since this layer addresses the requirements and operations of various mandatory fabric services like fabric build, directory, login, nameserver, management, etc. Next, using the OMNET++ discrete event simulator large fabrics are simulated. The results from the simulation are compared against the test bed traffic and the accuracy is demonstrated. Also, results and analysis of multiple simulations with increasing fabric size are presented.

  • microsoft exchange implementation on a distributed storage area network
    International Journal of Computers and Applications, 2008
    Co-Authors: Nagapramod Mandagere, Jerry Hamann, Suresh Muknahallipatna, Howard Johnson
    Abstract:

    AbstractThe ever-increasing demand for fast and reliable data storage has caused dramatic changes in the storage model. Direct attached storage (DAS) architecture, also known as server-centric architecture, is being replaced by the storage area network (SAN), leading to storage-centric architecture. In SAN storage devices exist completely independent of any computer (servers in particular). Multiple servers can access the same storage device without involvement of other servers. Recently, companies have been able to implement storage integration/sharing, remote backup/restoral, near-real-time disk mirroring/replication, and the like, using a new SAN architecture known as distributed storage area network (DSAN). The DSAN is multiple SANs interconnected using existing Internet Protocol (IP) networks to distribute storage over wide geographical areas. Even though DSANs provide additional capabilities to a SAN, the end-to-end latency (ETEL) due to large physical cable lengths (IP networks) imposes limitations...

  • LCN - Fibre Channel based storage area network Modeling using OPNET for Large Fabric Simulations: Preliminary Work
    32nd IEEE Conference on Local Computer Networks (LCN 2007), 2007
    Co-Authors: J. Staley, Suresh Muknahallipatna, Howard Johnson
    Abstract:

    Fibre channel based storage area networks have been a common implementation for data storage in enterprise data centers. As the size of the storage area network tends to grow along with geographical distribution leading to distributed storage area network, also known as large fabric, the network seems to exhibit scaling and stability issues. The scaling and stability issues seem to stem from the construction, route discovery, and management process of the network which are fibre channel-2 level traffic more than the actual I/O data transmission process. To determine the scaling and stability issues of a large fabric, an adequate tool is required. The tool is usually a discrete event simulator since an analytical or hardware simulator tool would not be able to handle the large size of the storage area network and model in detail. In this paper, the preliminary work on modeling and simulations of a fibre channel based storage area network using OPNET as a discrete event simulator are presented. As a preliminary step, the fibre channel host bus adapter and its interactions with the fabric login server of a fibre channel switch during the fabric login process is modeled at the fibre channel-2 level and preliminary simulations are performed.

Timothy D. Wilkinson - One of the best experts on this subject based on the ideXlab platform.

  • implementation of a 6 times 6 free space optical fiber ribbon switch for storage area networks
    Journal of Lightwave Technology, 2012
    Co-Authors: Hsihsir Chou, Fan Zhang, Timothy D. Wilkinson, N Collings, W A Crossland
    Abstract:

    A shutter-based free-space optical switching architecture capable of multicast transmission functionality has been proposed as a promising switching technology for storage area network applications. The main idea behind this type of switching architecture is that the system performance can be enhanced with a new electro-optical material, used for the shutters to increase switching speed. It can be distinguished from previous shutter-based optical switches which have been based on single channel to single channel switching, as we present a reconfigurable design of a 6 × 6 72-channel shutter-based optical switching core based on multimode fiber ribbon to multimode fiber ribbon switching. The design and implementation of a prototype 6 × 6 72-channel multi-mode fiber ribbon switch demonstrator utilizing a submicrosecond PLZT-based spatial light modulator as a shutter is reported. The light loss, crosstalk, and data switching characteristics of the implemented fiber ribbon switch from the evaluation tests were measured and are presented.

  • Free-space optical switching core for storage area network
    Optical Transmission Switching and Subsystems II, 2005
    Co-Authors: Fan Zhang, Neil Collings, William A. Crossland, Timothy D. Wilkinson, Mark Fan, Mohammad R. Taghizadeh, Andrew J. Waddie
    Abstract:

    storage area network (SAN) has gradually developed as the demand for storage capacity and fast access has increased. The traditional way of attaching storage directly to the servers over a SCSI bus has limited scalability. Several drawbacks and limitations have turned up. Switched Fibre Channel SAN resolves all of these issues. In this paper, the architecture of the switch fabric for the SAN is discussed. The complete design of the free-space optical switching core based on the diffractive element and the PLZT shutter is proposed.

  • Reconfigurable free-space optical cores for storage area networks
    IEEE Communications Magazine, 2005
    Co-Authors: Timothy D. Wilkinson, Neil Collings, B. Crossland, Fan Zhang
    Abstract:

    The role of the optical storage area network is becoming increasingly important in computer network architectures, with the amount of information being presented and requested on the Internet ever increasing. One of the key questions is what is the role of, and how do we control, an optical switch core within a SAN to optimize its performance. In this article we review two potential optical switch technologies and assess their performance as a SAN optical switch core.