Emc Corporation

Yottayotta, Inc.

Wayne T Karpoff

Brian Lake

Dale Hagglund

Geoff Hayward

Ron Unrau

Steven Richard Bromling

Roel Van Der Goot

Steve Bromling

Craig Graulich

Systems and methods for delivering streaming data content to a client device over a data communication network in response to a request for the data content from the client device. The client request is received by a server or a controller device that is typically located on a network switch device. If received by a server, the server sends a request to the controller device to control the transfer of the requested data to the client. The controller device includes the processing capability required for retrieving the streaming data and delivering the streaming data directly to the client device without involving the server system. In some cases, the controller device mirrors the data request to another controller device to handle the data processing and delivery functions. In other cases, the controller device coordinates the delivery of the requested data using one or more other similar controller devices in a pipelined fashion.

Method and system for providing multimedia information on demand over wide area networks

Network data storage systems and methods allow computers reading and writing data at a plurality of data centers separated by, potentially, large distances to replicate data between sites such that the data is protected from failures, including complete Site failures, while not allowing network latency to significantly impede the performance of read or write operations. Continued access to all data is provided even after a single failure of any component of the system or after any complete failure of all equipment located at any single geographic region or any failure that isolates access to any single geographic region. Write data is replicated synchronously from Active Sites, e.g., sites where servers are writing data to storage resources, to Protection Sites located sufficiently close to Active Sites such that network latency will not significantly impact performance, but sufficiently far apart such that a regional disaster is unlikely to affect both sites. Write data is then asynchronously copied to other sites, potentially including one or more Active sites, located at greater distances.

Systems and methods for obtaining ultra-high data availability and geographic disaster tolerance

A plurality of access nodes sharing access to data on a storage network implement a directory based cache ownership scheme. One node, designated as a global coordinator, maintains a directory (e.g., table or other data structure) storing information about I/O operations by the access nodes. The other nodes send requests to the global coordinator when an I/O operation is to be performed on identified data. Ownership of that data in the directory is given to the first requesting node. Ownership may transfer to another node if the directory entry is unused or quiescent. The distributed directory-based cache coherency allows for reducing bandwidth requirements between geographically separated access nodes by allowing localized (cached) access to remote data.

Systems and methods for providing distributed cache coherence

Storage virtualization systems and methods that allow customers to manage storage as a utility rather than as islands of storage which are independent of each other. A demand mapped virtual disk image of up to an arbitrarily large size is presented to a host system. The virtualization system allocates physical storage from a storage pool dynamically in response to host I/O requests, e.g., SCSI I/O requests, allowing for the amortization of storage resources-through a disk subsystem while maintaining coherency amongst I/O RAID traffic. In one embodiment, the virtualization functionality is implemented in a controller device, such as a controller card residing in a switch device or other network device, coupled to a storage system on a storage area network (SAN). The resulting virtual disk image that is observed by the host computer is larger than the amount of physical storage actually consumed.

Storage virtualization system with dynamic allocation of physical storage space

Storage virtualization system and methods

Write order fidelity (WOF) is maintained for totally-active implementations wherein a plurality of access nodes at geographically separated sites can concurrently read and/or write data in a 'totally active' fashion on a distributed data system. From the hosts' perspective at diverse geographic locations, a synchronous, cache-coherent view of data is provided. Data transfer is asynchronous. A time ordered data image is created and maintained so operations can be restarted after a partial system failure that causes loss of data not yet asynchronously transferred across the network, but that has been write-acknowledged to the originating host. Time ordered asynchronous data transfer is implemented as a pipeline of changes that reflect contributions from all nodes. WOF also improves network performance and lowers bandwidth consumption. Extensions can provide, in a totally-active context, features such as point-in-time snapshots, time firewalls, on-demand backend storage allocation, synchronous/asynchronous distribution of data, and continuous data protection.

Maintaining write order fidelity on a multi-writer system

Storage virtualization systems and methods that allow customers to manage storage as a utility rather than as islands of storage which are independent of each other. A demand mapped virtual disk image of up to an arbitrarily large size is presented to a host system. The virtualization system allocates physical storage from a storage pool dynamically in response to host I/O requests, e.g., SCSI I/O requests, allowing for the amortization of storage resources through a disk subsystem while maintaining coherency amongst I/O RAID traffic. In one embodiment, the virtualization functionality is implemented in a controller device, such as a controller card residing in a switch device or other network device, coupled to a storage system on a storage area network (SAN). The resulting virtual disk image that is observed by the host computer is larger than the amount of physical storage actually consumed.

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Wayne T Karpoff