Abstract: Embodiments herein provide for dynamic storage system configuration. In one embodiment, a storage controller is operable to configure a storage volume from a plurality of storage devices. The storage controller includes an interface operable to receive a first write I/O request from a host system, and to extract a storage configuration attribute from the first write I/O request. The storage controller also includes a processor communicatively coupled to the interface and operable to identify a storage configuration required by the first write I/O request based on the storage configuration attribute, to determine whether the storage volume comprises the required storage configuration of the first write I/O request, and to configure a portion of the storage volume according to the storage configuration required by the first write I/O request in response to a determination that the storage volume does not comprise the required storage configuration.

Abstract: Embodiments herein provide for dynamic storage system configuration. In one embodiment, a storage controller is operable to configure a storage volume from a plurality of storage devices. The storage controller includes an interface operable to receive a first write I/O request from a host system, and to extract a storage configuration attribute from the first write I/O request. The storage controller also includes a processor communicatively coupled to the interface and operable to identify a storage configuration required by the first write I/O request based on the storage configuration attribute, to determine whether the storage volume comprises the required storage configuration of the first write I/O request, and to configure a portion of the storage volume according to the storage configuration required by the first write I/O request in response to a determination that the storage volume does not comprise the required storage configuration.

Abstract: Methods and structure for improved shipping of I/O requests among multiple storage controllers of a clustered storage system. Minimal processing of a received I/O request is performed in a first controller to determine whether the I/O request is directed to a logical volume that is owned by the first controller or to a logical volume owned by another controller. For requests to logical volumes owned by another controller, the original I/O request is modified to indicate the target device address of the other controller. The first controller then ships the request to the other controller and configures DMA capabilities of the first controller to exchange data associated with the shipped request between the other controller and memory of the host system.

Abstract: Methods and systems for using one or more solid-state drives (SSDs) as a shared cache memory for a plurality of storage controllers coupled with the SSDs and coupled with a plurality of storage devices through a common switched fabric communication medium. All controllers share access to the SSDs through the switched fabric and thus can assume control for a failed controller by, in part, accessing cached data of the failed controller in the shared SSDs.

Abstract: Methods and systems for transferring ownership of a logical volume in a storage system comprising multiple storage controllers is provided. According to the method, the storage controllers are coupled for communication with a logical volume, wherein at least one storage device coupled with the storage controllers implements the logical volume. The method comprises identifying, at a first storage controller, a second storage controller to receive the logical volume. The method also comprises initiating a transfer of ownership of the logical volume from the first storage controller to the second storage controller by transferring metadata stored in a memory of the first storage controller to the second storage controller, the metadata existing in a native format that describes the configuration of the logical volume on the at least one storage device.

Abstract: Methods and system for implementing a clustered storage solution are provided. One embodiment is a storage controller that communicatively couples a host system with a storage device. The storage controller comprises an interface and a control unit. The interface is operable to communicate with the storage device. The control unit is operable to identify ownership information for a storage device, and to determine if the storage controller is authorized to access the storage device based on the ownership information. The storage controller is operable to indicate the existence of the storage device to the host system if the storage controller is authorized, and operable to hide the existence of the storage device from the host system if the storage controller is not authorized.

Abstract: Methods and systems for transferring ownership of a logical volume in a storage system comprising multiple storage controllers is provided. According to the method, the storage controllers are coupled for communication with a logical volume, wherein at least one storage device coupled with the storage controllers implements the logical volume. The method comprises identifying, at a first storage controller, a second storage controller to receive the logical volume. The method also comprises initiating a transfer of ownership of the logical volume from the first storage controller to the second storage controller by transferring metadata stored in a memory of the first storage controller to the second storage controller, the metadata existing in a native format that describes the configuration of the logical volume on the at least one storage device.

Abstract: Methods and system for implementing a clustered storage solution are provided. One embodiment is a storage controller that communicatively couples a host system with a storage device. The storage controller comprises an interface and a control unit. The interface is operable to communicate with the storage device. The control unit is operable to identify ownership information for a storage device, and to determine if the storage controller is authorized to access the storage device based on the ownership information. The storage controller is operable to indicate the existence of the storage device to the host system if the storage controller is authorized, and operable to hide the existence of the storage device from the host system if the storage controller is not authorized.

Abstract: Methods and structure for improved shipping of I/O requests among multiple storage controllers of a clustered storage system. Minimal processing of a received I/O request is performed in a first controller to determine whether the I/O request is directed to a logical volume that is owned by the first controller or to a logical volume owned by another controller. For requests to logical volumes owned by another controller, the original I/O request is modified to indicate the target device address of the other controller. The first controller then ships the request to the other controller and configures DMA capabilities of the first controller to exchange data associated with the shipped request between the other controller and memory of the host system.

Abstract: Methods and systems for using one or more solid-state drives (SSDs) as a shared cache memory for a plurality of storage controllers coupled with the SSDs and coupled with a plurality of storage devices through a common switched fabric communication medium. All controllers share access to the SSDs through the switched fabric and thus can assume control for a failed controller by, in part, accessing cached data of the failed controller in the shared SSDs.

Abstract: Apparatus and methods for improved tree data structure management in a storage controller. A tree assist circuit coupled with a tree memory is provided for integration in a storage controller. I/O processors of the storage controller transmit requests to the tree assist circuit to create, modify, and access tree data structures stored in the tree memory. In one exemplary embodiment, the tree assist circuit is adapted to manage AVL trees. The tree data structures may be used by the I/O processors of the storage controller to manage region lock requests, cache-line lookup request, and other storage management functions of the controller. The I/O processors of the controller may comprise suitable programmed general-purpose processors and/or fast-path I/O request processor circuits.

Abstract: Methods and systems for improved lock processing in a storage controller. Storage controllers that provide storage management features such as RAID storage controllers may concurrently process I/O requests received from attached host systems and I/O requests generated internally by the management processing in the controller. Such concurrent processing is coordinated by lock processing that allows affected storage areas to be locked during processing of an I/O operation. Features and aspects hereof allow such lock processing to lock regions flexibly defined by the controller. The flexible definition of the regions to be locked allows variance in the granularity of the locks required. Smaller granularity permits more concurrent I/O requests to be processed.