Avago Technologies General IP (singapore) Pte. Ltd.

Lsi Corporation

Lsi Logic Corporation

Parag Ranjan Maharana

Kishore Kaniyar Sampathkumar

Paresh Chatterjee

Basavaraj Gurupadappa Hallyal

Luca Bert

Sumanesh Samanta

Senthil Thangaraj

Saugata Das Purkayastha

Earl T Cohen

Gerald Edward Smith

Moby J Abraham

Gurpreet Singh Anand

Methods and structure are provided for cache load balancing in storage controllers that utilize Solid State Drive (SSD) caches. One embodiment is a storage controller of a storage system. The storage controller includes a host interface operable to receive Input and Output (I/O) operations from a host computer. The storage controller also includes a cache memory that includes an SSD. Further, the storage controller includes a cache manager that is distinct from the cache memory. The cache manager is able to determine physical locations in the multiple SSDs that are unused, to identify an unused location that was written to a longer period of time ago than other unused locations, and to store a received I/O operation in the identified physical location. Further, the cache manager is able to trigger transmission of the stored I/O operations to storage devices of the storage system for processing.

Cache load balancing in storage controllers

A storage subsystem can achieve more efficient I/O processing by enabling users to specify and pass out of band I/O hints comprising an object to be hinted, a hint type, and caching strategies associated with a hint type. A hinted object may be either a virtual device or a file. In addition to priority cache, hint types may include never-cache, sticky-cache, and volatile-cache. Hints may be passed via command-line or graphical-user interfaces.

Systems and methods for I/O processing using out-of-band hinting to block driver or storage controller

An apparatus comprising a memory and a controller. The memory may be configured to (i) implement a cache and (ii) store meta-data. The cache may comprise one or more cache windows. Each of the one or more cache windows comprises a plurality of cache-lines configured to store information. The controller is connected to the memory and configured to (A) process normal read/write operations in a first mode and (B) process special read/write operations in a second mode by (i) tracking a write followed by read condition on each of said cache windows and (ii) discarding data on the cache-lines associated with the cache windows after completion of the write followed by a read condition on the cache-lines.

System for efficient caching of swap I/O and/or similar I/O pattern(s)

A method and controller device for sharing computing resources in a virtualized environment having a plurality of virtual machines. The method includes assigning a portion of the computing resources to the plurality of virtual machines. The method also includes leasing by a first virtual machine at least a portion of the assigned computing resources of at least one second virtual machine. The first virtual machine leases computing resources from the at least one second virtual machine when the first virtual machine needs additional computing resources and at least a portion of the assigned computing resources of the at least one second virtual machine are not being used by the at least one second virtual machine.

Method and controller device for quality of service (QOS) caching in a virtualized environment

Methods and structure are provided for reducing the number of writes to a cache of a storage controller. One exemplary embodiment includes a storage controller that has a non-volatile flash cache memory, a primary memory that is distinct from the cache memory, and a memory manager. The memory manager is able to receive data for storage in the cache memory, to generate a hash key from the received data, and to compare the hash key to hash values for entries in the cache memory. The memory manager can write the received data to the cache memory if the hash key does not match one of the hash values. Also, the memory manager can modify the primary memory instead of writing to the cache if the hash key matches a hash value, in order to reduce the amount of data written to the cache memory.

Reducing writes to solid state drive cache memories of storage controllers

A method for virtual function boot in a system including a single-root I/O virtualization (SR-IOV) enabled server includes loading a PF driver of the PF of a storage adapter onto the server utilizing the virtual machine manager of the server; creating a plurality of virtual functions utilizing the PF driver, detecting each of the virtual functions on an interconnection bus, maintaining a boot list associated with the plurality of virtual functions, querying the storage adapter for the boot list utilizing a VMBIOS associated with the plurality of VMs, presenting the detected boot list to a VM boot manager of the VMM, and booting each of the plurality of virtual machines utilizing each of the virtual functions, wherein each VF of the plurality of VFs is assigned to a VM of the plurality of VMs via an interconnect passthrough between the VMM and the plurality of VMs.

Virtual function boot in multi-root I/O virtualization environments to enable multiple servers to share virtual functions of a storage adapter through a MR-IOV switch

A method and system for managing a cache for a host machine is disclosed. The method includes: indicating each cache line in the cache as being in a transitional meta-state when any virtual machine hosted on the host machine moves out of the host machine; each time a particular cache line is accessed, indicating that particular cache line as no longer in the transitional meta-state; and marking the cache lines still in the transitional meta-state as invalid when a virtual machine moves back to the host machine.

Subtractive validation of cache lines for virtual machines

In one embodiment, a Peripheral Component Interconnect Express (PCIe) Input/Output (I/O) device operable to perform Single Root I/O Virtualization (SR-IOV) is provided. The device comprises hardware registers implementing a PCIe configuration space for the device, and firmware implementing one or more SR-IOV virtual functions that each provide a virtual machine access to a subset of PCIe configuration space hardware registers for the device. The device further includes a hardware recovery register directly accessible by each of the virtual machines, and a control unit. The control unit is operable to detect a firmware fault at the I/O device and to update the hardware recovery register with information describing the firmware fault.

Methods and structure for single root input/output virtualization enhancement in peripheral component interconnect express systems

The invention relates to a method for computer signal processing data and command transfer over an interface and more particularly to a communication between peripheral firmware and a host processor or Basic Input/Output System (BIOS) on a Peripheral Component Interconnect (PCI) bus. In one embodiment, a device and method for reducing the load on the PCI Bus is described. In yet another embodiment, a device and method is described for constructing a variable length command block comprising message frames and aligning all message frames for a particular command block that are contiguous in memory.

Variable length command pull with contiguous sequential layout

The present invention is a system and method for supporting an alternative peer-to-peer communication over a network in a SAS cluster when a node cannot communicate with another node through a normal I/O bus (Serial SCSI bus). At startup, driver may establish the alternative path for communication but may not use it as long as there is an I/O Path available. In the present invention, two types of P2P calls, such as event notification calls and cluster operation calls may be supported.

System for providing an alternative communication path in a SAS cluster

A plurality of modes is provided for communicating between a host system and a peripheral storage system controller. A first communication mode may be selected from the plurality of communication modes based on a bit length required to communicate a physical address. During runtime, a switch from the first communication mode to a second communication mode may be performed in order to improve the efficiency of processing address requests at the storage system controller.

Address buffer mode switching for varying request sizes

The present invention is directed to a system and method for supporting an alternative peer-to-peer communication over a network in a SAS cluster when a node cannot communicate with another node through a normal I/O bus (Serial SCSI bus). At startup, driver may establish the alternative path for communication but may not use it as long as there is an I/O Path available. In the present invention, two types of P2P calls, such as event notification calls and cluster operation calls may be supported.

A method for providing online raid migration without non-volatile memory employs reconstruction of the RAID drives. In this manner, the method of the present invention protects online migration of data from power failure with little or no performance loss so that data can be recovered if power fails while migration is in progress, and migration may be resumed without the use of non-volatile memory.

Online RAID migration without non-volatile memory

A storage controller is provided that allows data mirroring with hotspare where all drives take part in data storage. For each stripe written, a drive is designated as the hotspare. The hotspare is not a dedicated drive. Rather, the hotspare rotates as stripes are written to the drives. Thus, every drive is involved in data storage and load may be balanced among more drives. Furthermore, since each drive takes part in data storage, reconstruction after a drive failure takes less time.

Growing community of inventors

Fremont, CA, United States of America

Parag Ranjan Maharana