Abstract: A file server having a redundant data elimination store responds to requests from clients for copies of space-reduced files. For reduced storage requirements and reduced processing time, a baseline version of unshared data blocks is created in the file server, and then the baseline version is space reduced by conversion to a stub version of shared data blocks, and then the file server responds to a request from a client for creation of one or more space-reduced copies by cloning the stub version. The file server may also respond to a request for creation of a modified space-reduced copy having specified data written at a specified offset. For example, the file server creates a respective modified copy of a virtual server image file for use by each client of the file server.

Abstract: Methods, systems, and computer program products for managing quality of service for shared storage accessed by a plurality of nodes are disclosed. According to one method, at a node of a plurality of nodes sharing access to a first disk array, quality-of-service (QoS) metadata associated with a portion of the disk array are requested from a server, wherein the QoS metadata includes at least one performance criterion for the portion of the disk array. I/O performance is monitored for the portion of the disk array in response to receiving the QoS metadata. The monitored I/O performance is compared with the QoS metadata. Based upon the comparison of the monitored I/O performance with the QoS metadata, it is determined whether a QoS violation has occurred. In response to determining that a QoS violation has occurred, the server is requested to migrate data associated with the portion of the disk array.

Abstract: A data storage device includes a device interface for receiving data access requests, a plurality of non-volatile memory devices and a controller that accesses the non-volatile memory devices in response to the received data access requests. The plurality of non-volatile memory devices include at least one of flash memory; compact flash memory; magnoresistive RAM; ferroelectric RAM; any type of volatile memories, such as dynamic and static RAM, maintained as non-volatile with the use of a power subsystem; mechanical memory devices and microelectromechanical memory devices.

Abstract: A shared line coherency method and mechanism for maintaining coherency of shared lines of information. Each line will have a single home node and may have a plurality of leaf nodes and a single owner node. The owner node is the first node to access the line or the last node to modify the line and tracks all leaf nodes. All requests to a line are directed to the home node of the line, which provides a copy of the line to the requesting node and forwards the request to the owner node for completion. Each node maintains a line tag for each line resident in the node and a line tag includes a line state value and an identifier of a current node to which the node is to direct communications relevant to the line.