Netapp, Inc.

Lsi Corporation

Howard Young

Srinivasa Nagaraja Rao

Gordon L Larimer

Mukul Kotwani

Dante Cinco

Kartik D Agarwal

Thomas P Anderson

Methods and apparatus for cut-through cache memory management in write command processing on a mirrored virtual volume of a virtualized storage system, the virtual volume comprising a plurality of physical storage devices coupled with the storage system. Features and aspects hereof within the storage system provide for receipt of a write command and associated write data from an attached host. Using a cut-through cache technique, the write data is stored in a cache memory and transmitted to a first of the plurality of storage devices as the write data is stored in the cache memory thus eliminating one read-back of the write data for transfer to a first physical storage device. Following receipt of the write data and storage in the cache memory, the write data is transmitted from the cache memory to the other physical storage devices.

Methods and apparatus for cut-through cache management for a mirrored virtual volume of a virtualized storage system

A system and method for arbitrating exchange identifier assignments for I/O operations are disclosed. In an exemplary embodiment, the method comprises receiving, by a storage system, a data command from a host system. The data command is directed to a virtual device of the storage system, the virtual device comprising a plurality of physical devices of the storage system. A range of exchange identifier values are allocated to the data command. The range may include a predefined number of exchange identifiers, the predefined number determined prior to the receiving of the data command. A plurality of I/O operations corresponding to the data command are issued, where each of the plurality of I/O operations is directed to a physical device of the plurality of physical devices of the storage system. An exchange identifier within the range of exchange identifier values is associated with each of the plurality of I/O operations.

Methods and apparatus for managing asynchronous dependent I/O for a virtual fibre channel target

Methods and apparatus for managing exchange IDs for multiple asynchronous dependent I/O operations generated for virtual Fibre Channel (FC) target volumes. Features and aspects hereof allocate a range of exchange identifier (X_ID) values used in issuing a plurality of physical I/O operations to a plurality of physical FC target devices that comprise the virtual FC target volume. The plurality of physical I/O operations are dependent upon one another for completion of the original request to the virtual FC target volume and allow substantially parallel operation of the plurality of physical FC target devices. A primary X_ID is selected from the range of allocated X_ID values for communications with the attached host system that generated the original request to the virtual FC target volume.

Methods and apparatus for expanded capacity virtual volumes in a virtualized storage system. A storage controller of the storage system parses a SCSI command block as it is received to generate a tag value indicating a segment of a virtual volume to which the command block is directed. The tag value is used to select one of a plurality of mapping segment objects stored in a memory of the controller. Each mapping segment objects maps logical block addresses of a corresponding segment of a corresponding virtual volume to physical storage addresses on the physical storage devices that comprise the virtual volume. An I/O processing circuit of the controller then processes the SCSI command block in accordance with the mapping information in the selected mapping segment object. In one exemplary embodiment, each segment of a virtual volume comprises 2 terabytes of storage capacity of the virtual volume.

Apparatus and methods for managing expanded capacity of virtual volumes in a storage system

Apparatus and methods for improved efficiency in accessing meta-data in a storage controller of a virtualized storage system. Features and aspects hereof walk/retrieve meta-data for one or more other I/O requests when retrieving meta-data for a first I/O request. The meta-data may include mapping information for mapping logical addresses of the virtual volume. Meta-data may also include meta-data associated with higher level, enhanced data services provide by or in conjunction with the storage system. Enhanced data services may include features for synchronous mirroring of a volume and/or management of time-based snapshots of the content of a virtual volume.

Apparatus and methods for look-ahead virtual volume meta-data processing in a storage controller

Apparatus and methods for real-time routing of received frames in a split-path architecture storage controller. In one exemplary embodiment, a split-path storage controller comprises a soft-path I/O processor for processing of any received frames and comprises a fast-path I/O processor for efficient processing of common read and write command. A content parsing circuit of the storage controller parses each frame substantially concurrent with reception of the frame and selects an I/O processor for processing of an initial frame and subsequent related frames. Received frames are then routed concurrently as they are received for processing by the selected I/O processor of the multiple I/O processors of the split-path storage controller.

Apparatus and methods for real-time routing of received commands in a split-path architecture storage controller

Systems and methods herein provide for load balancing Fiber Channel traffic. In this regard, a Fiber Channel load balancer may be operable to monitor Fiber Channel paths coupled to a host bus adapter and determine the speeds of the Fiber Channel ports within the Fiber Channel paths. The Fiber Channel load balancer may also be operable to determine certain characteristics of the Fiber Channel traffic being passed over the Fiber Channel paths. For example, a load balancer may determine Fiber Channel traffic sizes of pending requests and, based in part on the traffic sizes and operable normalized speeds of the Fiber Channel ports, adaptively route the pending original traffic across the Fiber Channel ports.

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Thousand Oaks, CA, United States of America

Howard Young