Abstract: Methods and structure for managing cache memory for a storage controller. One exemplary embodiment a Redundant Array of Independent Disks (RAID) storage controller. The storage controller includes an interface operable to receive Input/Output (I/O) requests from a host, a Direct Memory Access (DMA) module, a memory comprising cache data for a logical volume, and a control unit. The control unit is able to generate Scatter Gather Lists (SGLs) that indicate the location of cache data for incoming read requests. Each SGL is stored in the memory, and at least one SGL points to cache data that is no longer indexed by the cache. The control unit is also able to service an incoming read request based on the SGL, by directing the DMA module to transfer the cache data that is no longer indexed to the host.

Abstract: Methods and structure for formatting and processing Scatter Gather Lists (SGLs). One exemplary embodiment is a storage controller that includes a cache memory storing data for a logical volume, and a control unit. The control unit is able to service an Input/Output (I/O) request based on a Scatter Gather List (SGL) that refers to the cache memory, the SGL comprising multiple entries that each include a flag field and an identifier (ID) field. The entries are assigned to categories that are each associated with a different set of stored processing instructions. The control unit is able to identify a category for an entry based on a combination of both flag field and ID field for the entry, and the control unit is able to process the entry using the set of instructions associated with the identified category.

Abstract: Methods and structure for formatting and processing Scatter Gather Lists (SGLs). One exemplary embodiment is a storage controller that includes a cache memory storing data for a logical volume, and a control unit. The control unit is able to service an Input/Output (I/O) request based on a Scatter Gather List (SGL) that refers to the cache memory, the SGL comprising multiple entries that each include a flag field and an identifier (ID) field. The entries are assigned to categories that are each associated with a different set of stored processing instructions. The control unit is able to identify a category for an entry based on a combination of both flag field and ID field for the entry, and the control unit is able to process the entry using the set of instructions associated with the identified category.

Abstract: Methods and structure for managing cache memory for a storage controller. One exemplary embodiment a Redundant Array of Independent Disks (RAID) storage controller. The storage controller includes an interface operable to receive Input/Output (I/O) requests from a host, a Direct Memory Access (DMA) module, a memory comprising cache data for a logical volume, and a control unit. The control unit is able to generate Scatter Gather Lists (SGLs) that indicate the location of cache data for incoming read requests. Each SGL is stored in the memory, and at least one SGL points to cache data that is no longer indexed by the cache. The control unit is also able to service an incoming read request based on the SGL, by directing the DMA module to transfer the cache data that is no longer indexed to the host.

Abstract: Structure is disclosed for a non-blocking SAS architecture utilizing virtual connections between SAS devices. One embodiment comprises a SAS expander. The SAS expander comprises a plurality of physical links (PHYs) and a Virtual Connection Manager (VCM) coupled with the plurality of PHYs. The VCM exchanges information over a plurality of concurrently established virtual pathways between a first PHY of the plurality of PHYs and a second PHY of the plurality of PHYs.

Abstract: A system includes a PCIe controller coupled to a device through a nontransparent PCIe bridge. The controller is operable to direct I/O operations to the device on behalf of a host system. The system also includes a PCIe driver operable within the host system to generate I/O request descriptors that specify movement of data from the PCIe controller to the host system as well as from the host system to the PCIe controller. The PCIe controller processes the I/O request descriptors and determines which device is involved in the specified movement of data. The PCIe controller generates I/O commands that contain routing information for the device (e.g., memory addresses and steering information) to route the data between the memory address of the host system and the memory address of the device, bypassing a memory of the PCIe controller.

Abstract: Disclosed is a system and method for using a programmable sequencer to produce a required command for a particular standard, or format, being used by the PCIe disk drive. A PCIe disk drive may support a different standard, or format. A mix of any number of different standards, or formats, is permitted in the system and method. For each message, a different set of instructions can be selected for the conversion process.

Abstract: Disclosed is a storage system. The storage system includes a redundant array of inexpensive disks (RAID) controller. The RAID controller includes a flash memory controller coupled to a flash memory. The flash memory controller may perform background management tasks. These include logging and error reporting, address translation, cache table management, bad block management, defect management, wear leveling, and garbage collection. The array controller also allows the flash memory to be divided into multiple mappings.

Abstract: A region lock (RL) method and system for ensuring data integrity is disclosed. The method and system in accordance with the present disclosure works in conjunction with a balanced-tree based RL scheme. By eliminating steps and checks that in most cases are unnecessary, the relatively high overhead associated with the balanced-tree based RL scheme may be reduced. For instance, the solution in accordance with the present disclosure may utilize a hash table to determine whether RL overlap checks may be bypassed for certain I/O commands. Since the new solution requires very little processing, therefore by reducing unnecessary RL overlap checks, RL overhead may be dramatically reduced and may lead to significant increases in overall system performance.

Abstract: Disclosed is a system and method for using a programmable sequencer to produce a required command for a particular standard, or format, being used by the PCIe disk drive. A PCIe disk drive may support a different standard, or format. A mix of any number of different standards, or formats, is permitted in the system and method. For each message, a different set of instructions can be selected for the conversion process.

Abstract: Disclosed is a power isolation and backup system. When a power fail condition is detected, temporary storage is flushed to an SDRAM. After the flush, interfaces are halted, and power is removed from most of the chip except the SDRAM subsystem. The SDRAM subsystem copies data from an SDRAM to a flash memory. On the way, the data may be encrypted, and/or a data integrity signature calculated. To restore data, the SDRAM subsystem copies data from the flash memory to the SDRAM. On the way, the data being restored may be decrypted, and/or a data integrity signature checked.

Abstract: Disclosed is a storage device interface. The storage device interface includes a plurality of PCIe device request engines. These PCIe device request engines receive I/O commands formatted for a respective one of a plurality of PCIe storage device communication standards. The storage device interface also includes a plurality of PCIe device completion engines. These PCIe device completion engines receive notifications of command completions from a plurality of PCIe storage devices that communicate using the aforementioned plurality of PCIe storage device communication standards. These notifications are validated. If an error is detected, processing of notifications of command completions associated with that device are blocked until the error is resolved. The plurality of PCIe device request engines and the PCIe device completion engines operate concurrently to process received I/O commands and received command completions.

Abstract: The present invention is directed to a boot appliance for a data storage system. The boot appliance is a self-contained, pre-configured device that serves as a boot device for multiple servers. The boot appliance contains multiple hard drives which are configured into one or more RAID volumes. Each volume is divided into multiple partitions, with each partition serving as the boot drive for any server connected to it. The boot appliance provides its own environmental controls and Ethernet connection which may be used for providing alerts regarding the health of the components of the boot appliance and/or data storage system to a monitoring system, such as a network management system. The boot appliance may provide a boot drive and operating system image to multiple servers at the same time.

Abstract: A system includes a PCIe controller coupled to a device through a nontransparent PCIe bridge. The controller is operable to direct I/O operations to the device on behalf of a host system. The system also includes a PCIe driver operable within the host system to generate I/O request descriptors that specify movement of data from the PCIe controller to the host system as well as from the host system to the PCIe controller. The PCIe controller processes the I/O request descriptors and determines which device is involved in the specified movement of data. The PCIe controller generates I/O commands that contain routing information for the device (e.g., memory addresses and steering information) to route the data between the memory address of the host system and the memory address of the device, bypassing a memory of the PCIe controller.

Abstract: Structure is disclosed for a non-blocking SAS architecture utilizing virtual connections between SAS devices. One embodiment comprises a SAS expander. The SAS expander comprises a plurality of physical links (PHYs) and a Virtual Connection Manager (VCM) coupled with the plurality of PHYs. The VCM exchanges information over a plurality of concurrently established virtual pathways between a first PHY of the plurality of PHYs and a second PHY of the plurality of PHYs.

Abstract: Apparatus and associated methods for a simplified multi-client initiator/target within a SAS device. Features and aspects hereof provide a simplified initiator/target component to enable cost reduction and simplification of SAS devices requiring only limited initiator/target functionality. In one embodiment, a SAS expander may incorporate simplified SSP/STP/SMP initiator/target features and aspects hereof to permit simple management of devices coupled to the expander or coupled downstream through other expanders. The simplified multi-client initiator/target suffices for simple management functions while reducing cost and complexity of the SAS expander. Features and aspects hereof may be implemented with shared circuits for each of multiple client protocols coupled with firmware operable in a general or special purpose processor embedded in the SAS device.

Abstract: The present invention is directed to a boot appliance for a data storage system. The boot appliance is a self-contained, pre-configured device that serves as a boot device for multiple servers. The boot appliance contains multiple hard drives which are configured into one or more RAID volumes. Each volume is divided into multiple partitions, with each partition serving as the boot drive for any server connected to it. The boot appliance provides its own environmental controls and Ethernet connection which may be used for providing alerts regarding the health of the components of the boot appliance and/or data storage system to a monitoring system, such as a network management system. The boot appliance may provide a boot drive and operating system image to multiple servers at the same time.

Abstract: The present invention is directed to an information handling system device for operatively coupling with a device implementing Input/Output (I/O) virtualization for data transmission. The information handling system device may be configured for executing an operating system control program to manage one or more guest operating systems on the information handling system device. The operating system control program may include a paravirtualization driver for formulating a work queue entry according to the I/O virtualization of the device. Data may be transmitted between the one or more guest operating systems and the device via the paravirtualization driver.

Abstract: Disclosed is a method that simultaneously transfers DMA data from a peripheral device to a hardware assist function and processor memory. A first DMA transfer is configured to transfer data from the peripheral to a peripheral DMA engine. While receiving the data, the DMA engine simultaneously transfers this data to processor memory. The DMA engine also transfers a copy of the data to a hardware assist function. The DMA engine may also simultaneously transfer data from processor memory to a peripheral device while transferring a copy to a hardware assist function.

Abstract: A hardware automated IO path, comprising a message transport unit for transporting an IO request to a local memory via a DMA operation and determining a LMID for associating with a request descriptor of the IO request; a fastpath engine for validating the request descriptor and creating a fastpath descriptor based on the request descriptor; a data access module for performing an IO operation based on the fastpath descriptor and posting a completion message into the fastpath completion queue upon a successful completion of the IO operation. The fastpath engine is further configured for: receiving the completion message, releasing the IO request stored in the local memory, and providing a reply message based on the completion message. The message transport unit is further configured for providing the reply message in response to the IO request.