Abstract: A method includes: storing a first data extent on a physical medium, wherein the physical medium is divided into a plurality of storage blocks, wherein each of the storage blocks has a size that is different than a size of the first data extent, further wherein the first data extent is stored to a first block of the plurality of storage blocks; generating a descriptor for the first data extent, wherein the descriptor indicates that the first data extent starts within the first block of the plurality of blocks and indicates an offset from the beginning of the first block at which the first data extent starts; and storing the descriptor within the first block.

Abstract: A method includes: storing a first data extent on a physical medium, wherein the physical medium is divided into a plurality of storage blocks, wherein each of the storage blocks has a size that is different than a size of the first data extent, further wherein the first data extent is stored to a first block of the plurality of storage blocks; generating a descriptor for the first data extent, wherein the descriptor indicates that the first data extent starts within the first block of the plurality of blocks and indicates an offset from the beginning of the first block at which the first data extent starts; and storing the descriptor within the first block.

Abstract: A method includes: storing a first data extent on a physical medium, wherein the physical medium is divided into a plurality of storage blocks, wherein each of the storage blocks has a size that is different than a size of the first data extent, further wherein the first data extent is stored to a first block of the plurality of storage blocks; generating a descriptor for the first data extent, wherein the descriptor indicates that the first data extent starts within the first block of the plurality of blocks and indicates an offset from the beginning of the first block at which the first data extent starts; and storing the descriptor within the first block.

Abstract: A method includes: storing a first data extent on a physical medium, wherein the physical medium is divided into a plurality of storage blocks, wherein each of the storage blocks has a size that is different than a size of the first data extent, further wherein the first data extent is stored to a first block of the plurality of storage blocks; generating a descriptor for the first data extent, wherein the descriptor indicates that the first data extent starts within the first block of the plurality of blocks and indicates an offset from the beginning of the first block at which the first data extent starts; and storing the descriptor within the first block.

Abstract: A system and method are provided for backing up and recovering data that allows the data to be modified and backed up even while recovery is still in progress. In some embodiments, the method includes performing a data recovery procedure on a computing system. The data recovery procedure includes identifying a set of data objects stored on a recovery system; retrieving the set of data objects; and storing data of the retrieved set of data objects to at least one storage device. Data objects may be prioritized so that data that is in demand is retrieved first. Data that is modified during the data recovery procedure is tracked and backed up to an object-storage system during the data recovery procedure. In some embodiments, backing up the modified data is part of an incremental backup procedure that excludes data objects that contains only unmodified data.

Abstract: Methods and structure for devices that implement multiple versions of the Serial Attached Small Computer System Interface (SAS) protocol. One exemplary embodiment comprises a SAS device that includes at least one physical link (PHY) that supports a specified generation of SAS protocols, and at least one PHY that supports a different generation of SAS protocols and that does not support the specified generation of SAS protocols. The SAs device also includes an Input/Output (I/O) processor able to select a PHY to service a SAS connection, based on the generation of SAS protocols supported by the PHY.

Abstract: A method includes: storing a first data extent on a physical medium, wherein the physical medium is divided into a plurality of storage blocks, wherein each of the storage blocks has a size that is different than a size of the first data extent, further wherein the first data extent is stored to a first block of the plurality of storage blocks; generating a descriptor for the first data extent, wherein the descriptor indicates that the first data extent starts within the first block of the plurality of blocks and indicates an offset from the beginning of the first block at which the first data extent starts; and storing the descriptor within the first block.

Abstract: A system and method for recovering a dataset is provided that analyzes the dataset as it currently exists in order to determine those portions that do not need to be recovered. In some embodiments, the method includes identifying a dataset stored on a set of storage devices and corresponding to a first point in time. A request to restore the dataset to a second point in time is received, and a subset of the dataset is identified that is different between the first point in time and the second point in time. Data associated with the subset is selectively retrieved that corresponds to the second point in time, and the retrieved data is merged with the dataset stored on the set of storage devices. The two points in time may have any relationship, and in various examples, the method performs a roll-back or a roll-forward of the dataset.

Abstract: A system and method are provided for backing up and recovering data that allows the data to be modified and backed up even while recovery is still in progress. In some embodiments, the method includes performing a data recovery procedure on a computing system. The data recovery procedure includes identifying a set of data objects stored on a recovery system; retrieving the set of data objects; and storing data of the retrieved set of data objects to at least one storage device. Data objects may be prioritized so that data that is in demand is retrieved first. Data that is modified during the data recovery procedure is tracked and backed up to an object-storage system during the data recovery procedure. In some embodiments, backing up the modified data is part of an incremental backup procedure that excludes data objects that contains only unmodified data.

Abstract: Methods and structure for detecting that arbitration is delaying discovery. One embodiment is a Serial Attached Small Computer System Interface (SAS) expander. The SAS expander includes multiple SAS ports, a port monitor, and a controller. The port monitor is able to track physical link events during arbitration for at least one of the ports while discovery is in progress at the expander, and to detect based on the physical link events that arbitration is delaying discovery. The controller is able to prioritize discovery requests at the expander responsive to detecting that arbitration is delaying discovery.

Abstract: Methods and structure for lane-based multiplexing of physical links are provided. In one embodiment, a Serial Attached Small Computer System Interface (SAS) device is provided. The SAS device comprises a physical link and a controller. The controller is able to time division multiplex the physical link into multiple lanes, and to manage a first connection along one or more of the lanes of the physical link. The controller is further able to detect a request for a second connection, to determine a link rate for the second connection, to select a number of additional lanes at the physical link based on the link rate for the second connection, and to manage the second connection along the additional lanes while the first connection is being managed.

Abstract: Methods and structure for devices that implement multiple versions of the Serial Attached Small Computer System Interface (SAS) protocol. One exemplary embodiment comprises a SAS device that includes at least one physical link (PHY) that supports a specified generation of SAS protocols, and at least one PHY that supports a different generation of SAS protocols and that does not support the specified generation of SAS protocols. The SAs device also includes an Input/Output (I/O) processor able to select a PHY to service a SAS connection, based on the generation of SAS protocols supported by the PHY.

Abstract: A method for managing a request for an outbound connection is provided. The method includes the step of receiving the request for the outbound connection. The request includes a specified connection speed. The method also includes the step of comparing the request for the outbound connection to a plurality of outbound connection options. A further step of the method includes selecting an outbound connection from the plurality of outbound connection options. The selected outbound connection has a connection speed at least equal to the specified connection speed. The selected outbound connection also has the lowest connection speed of the outbound connection options having a connection speed at least equal to the specified connection speed.

Abstract: The disclosure is directed to a system and method for managing connections across a plurality of phys including at least one phy having a first link rate and at least one phy having a second link rate. At least one connection request including a selected link rate is received from an initiator. An arbitration in progress (AIP) delay is provided when at least one phy having the selected link rate or higher is not available. During the AIP delay, a link manager continues to check for a phy having the selected link rate or higher. The link manager completes the connection request if a phy having the selected link rate or higher becomes available before the AIP delay ends.

Abstract: Methods and structure for detecting that arbitration is delaying discovery. One embodiment is a Serial Attached Small Computer System Interface (SAS) expander. The SAS expander includes multiple SAS ports, a port monitor, and a controller. The port monitor is able to track physical link events during arbitration for at least one of the ports while discovery is in progress at the expander, and to detect based on the physical link events that arbitration is delaying discovery. The controller is able to prioritize discovery requests at the expander responsive to detecting that arbitration is delaying discovery.

Abstract: Systems and methods presented herein provide for the management of link rates for connecting targets devices (e.g., storage devices) to initiators (e.g., host systems). In one embodiment, an expander includes a plurality of PHYs including a PHY having a first link rate and a PHY having a second link rate that is different than the first link rate. The expander also includes a link manager communicatively coupled to the PHYs and operable to process a connection request from an initiator for the first link rate, extract a timer from the connection request, and determine whether the first link rate is available. The link manager is also operable to start the timer when the link manager determines that the first link rate is unavailable and issue a response to the initiator to inform the initiator that the timer has started and that connection at the first link rate is delayed.

Abstract: Methods and systems are provided for adaptive interconnect bridging. A first interconnect type may be determined for a first bridging interface, which is configurable to support a first plurality of interconnect types; and a second interconnect type may be determined for a second bridging interface that is configurable to support a second plurality of interconnect types. The first bridging interface may then be configured based on the first interconnect type, and the second bridging interface may then be configured based on the second interconnect type. Further, the orientation of bridging may be configured based on the determined interconnect types as well as on functions of devices attached to the first bridging interface and the second bridging interface. One of the first bridging interface and the second bridging interface may be assigned a function of ‘initiator’ whereas the other one of the first bridging interface and the second bridging interface a function of ‘target’.

Abstract: Systems and methods presented herein provide for managing connections in a SAS domain comprising at least first and second expanders. The first expander detects a failure of the initiator and indicates a change in the SAS domain to the second expander. The second expander detects an increase in arbitration wait time for a connection between the initiator and the target device, determines a race condition exists in the second expander, denies the connection between the initiator and the target device, directs the target device to wait for another connection, performs a discovery of the domain based on the discovery request from the first expander, and prevents a subsequent connection by the target device to the initiator after discovery completes.

Abstract: A system and method for servers to belong to a cascaded cluster of nodes (or servers) is disclosed. Servers share storage in common without the need of an external element such as a switch and or external storage device. SAS technology is used with direct attached drives in each node, and connections between each node, to emulate a SAN environment through a cascaded SAS topology. SAS HBAs each containing an SAS expander, connect elements internal to each server with elements external to each. This cascaded DAS clustering enables bi-directional traffic from each server in the cluster to all other servers and their attached drives.

Abstract: Systems and methods presented herein provide for managing connections in a SAS domain comprising at least first and second expanders. The first expander detects a failure of the initiator and indicates a change in the SAS domain to the second expander. The second expander detects an increase in arbitration wait time for a connection between the initiator and the target device, determines a race condition exists in the second expander, denies the connection between the initiator and the target device, directs the target device to wait for another connection, performs a discovery of the domain based on the discovery request from the first expander, and prevents a subsequent connection by the target device to the initiator after discovery completes.