摘要:
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.
摘要:
Methods and system are provided for exposing logical volumes to host systems and storage controllers in a consistent manner across a clustered storage system. One embodiment is a storage controller. The storage controller is operable to communicate with other storage controllers within the clustered storage system. The storage controller is further operable to generate a proposed Logical Unit Number (LUN) for a logical volume provisioned at the storage devices, and to communicate with each of the other storage controllers within the clustered storage system requesting that the other storage controllers determine if the proposed LUN is in use. If the proposed LUN is not in use, then storage controller assigns the proposed LUN to the logical volume. If the LUN is in use, then the storage controller generates a new proposed LUN and re-tries communication with the other storage controllers until a unique LUN is found.
摘要:
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.
摘要:
Disclosed is a system with multiple virtual machines passing I/O requests via a shared memory space. A flag in shared memory is set to a first state in response to a first hypervisor I/O interrupt to indicate that an I/O processing routine is active (running). I/O requests are retrieved from an I/O queue in the shared memory by the I/O processing routine. Based on an indicator that there are no I/O requests remaining in said I/O queue, the shared flag is set to a second state to indicate that the I/O processing routine is deactivated (sleeping). In response to said shared flag being in the second state, when new I/O requests are going to be made, a second hypervisor I/O interrupt is generated. In response to said shared flag being in said first state, I/O requests are inserted into the I/O queue without generating a second hypervisor I/O interrupt.
摘要:
Methods and structure for task management in storage controllers of a clustered storage system. An initiator storage controller of the clustered storage system ships I/O requests for processing to a target storage controller of the system. Responsive to a need to abort a previously shipped I/O request, the initiator storage controller transmits a task management message to the target storage controller. The task management message identifies one or more previously shipped I/O requests to be aborted. The target storage controller processes the received task management message in due course of processing requests and completes processing for the aborted previously shipped request in an orderly manner. Resources associated with the aborted previously shipped requests are release within both controllers.
摘要:
Methods and structure for load balancing of background tasks between storage controllers are provided. An exemplary active storage controller comprises a front-end interface that receives host Input/Output (I/O) requests directed to a logical volume, a back-end interface that couples with one or more of storage devices provisioning the logical volume, and a control unit. The control unit processes the host I/O requests directed to the logical volume, identifies a background processing task distinct from the host I/O requests and related to the logical volume, and assigns the background processing task to a passive storage controller for processing.
摘要:
Methods and system are provided for exposing logical volumes to host systems and storage controllers in a consistent manner across a clustered storage system. One embodiment is a storage controller. The storage controller is operable to communicate with other storage controllers within the clustered storage system. The storage controller is further operable to generate a proposed Logical Unit Number (LUN) for a logical volume provisioned at the storage devices, and to communicate with each of the other storage controllers within the clustered storage system requesting that the other storage controllers determine if the proposed LUN is in use. If the proposed LUN is not in use, then storage controller assigns the proposed LUN to the logical volume. If the LUN is in use, then the storage controller generates a new proposed LUN and re-tries communication with the other storage controllers until a unique LUN is found.
摘要:
Methods and structure for improved buffer management in a storage controller. A plurality of processes in the controller each transmits buffer management requests to buffer management control logic. A plurality of reserved portions and a remaining non-reserved portion are defined in a shared pool memory managed by the buffer management control logic. Each reserved portion is defined as a corresponding minimum amount of memory of the shared pool. Each reserved portion is associated with a private pool identifier. Each allocation request from a client process supplies a private pool identifier for the associated buffer to be allocated. The buffer is allocated from the reserved portion if there sufficient available space in the reserved portion identified by the supplied private pool identifier. Otherwise, the buffer is allocated if sufficient memory is available in the non-reserved portion. Otherwise the request is queued for later re-processing.
摘要:
Methods and structure for load balancing of background tasks between storage controllers are provided. An exemplary active storage controller comprises a front-end interface that receives host Input/Output (I/O) requests directed to a logical volume, a back-end interface that couples with one or more of storage devices provisioning the logical volume, and a control unit. The control unit processes the host I/O requests directed to the logical volume, identifies a background processing task distinct from the host I/O requests and related to the logical volume, and assigns the background processing task to a passive storage controller for processing.
摘要:
Methods and structure for improved processing of fast path I/O requests in a clustered storage system. In a storage controller of a clustered storage system, the controller comprises a fast path I/O request processing circuit tightly coupled with host system drivers for fast processing of requests directed to storage devices of a logical volume. The controller also comprises a logical volume I/O processing stack (typically implemented as programmed instructions) for processing I/O requests from a host system directed to a logical volume. Based on detecting a change of ownership of a device or volume and/or a change to logical to physical mapping of a logical volume, fast path I/O requests may be converted to logical volume requests based on mapping context information within the fast path I/O request and shipped within the clustered storage system for processing.