Lsi Corporation

Lsi Logic Corporation

Timothy R Snider

Donald Roman Humlicek

Brian Dennis McKean

Rodney A Dekoning

Martin Jess

Kevin Lee Kidney

Charles E Nichols

Rexford Alan Hill

James A Lynn

John Logan

John V Sherman

Marlin J Gwaltney

Dale L Harris

A method for managing data movement in a multi-level cache system includes selecting at least one outgoing data block from a primary cache when an unallocated space of the primary cache has reached a minimum threshold, initiating a de-stage process for de-staging the outgoing data block, and terminating the de-stage process when the unallocated space has reached an upper threshold. The de-stage process includes storing the outgoing data block in a secondary cache when a cache hit has occurred before. The cache hit may be an actual cache hit or a 'ghost' cache hit wherein only metadata is stored in the secondary cache. A method for de-staging an outgoing data block from a higher level cache which includes storing an outgoing data block in a lower level cache when a cache hit rate satisfies a predetermined condition and storing metadata in the lower level cache is also disclosed.

Methods for managing data movement and destaging data in a multi-level cache system utilizing threshold values and metadata

Methods and structure for reprogramming firmware in a storage controller using a virtual machine management (VMM) environment. A storage process (current firmware) in the storage controller operates in a current virtual machine (VM) under control of a hypervisor. Reprogrammed (new) firmware is loaded into a new virtual machine under control of the hypervisor. The new firmware initializes and directs the current firmware to quiesce its processing. The new firmware also requests the hypervisor to map data in the memory space of the current virtual machine into the memory space of the new virtual machine and to transfer ownership/control of devices and network addresses from the current virtual machine to the new virtual machine. The new firmware operating on the new virtual machine then takes control of the storage controller and resumes processing of requests.

Methods and structure for near-live reprogramming of firmware in storage systems using a hypervisor

Methods and systems for data reconstruction following drive failures may include: storing data across two or more drives in one or more data stripes, each data stripe including two or more drive extents; detecting a degradation of a drive containing a drive extent associated with a first data stripe; assigning a reconstruction priority to the drive extent associated with the first data stripe; detecting a degradation of a drive containing a drive extent associated with a second data stripe; and assigning a reconstruction priority to the drive extent associated with the second data stripe.

Method and system for data reconstruction after drive failures

Methods and structure for automated determination and reconfiguration of the size of a cache memory in a storage system. Features and aspects hereof generate historical information regarding frequency of hits on cache lines in the cache memory. The history maintained is then analyzed to determine a desired cache memory size. The historical information regarding cache memory usage may be communicated to a user who may then direct the storage system to reconfigure its cache memory to a desired cache memory size. In other embodiments, the storage system may automatically determine the desired cache memory size and reconfigure its cache memory. The method may be performed automatically periodically, and/or in response to a user's request, and/or in response to detecting thrashing caused by least recently used (LRU) cache replacement algorithms in the storage system.

Methods and structure for determining cache size in a storage system

methods and systems for monitoring data activity may include various operations, including, but not limited to: modifying a value of at least one counter in response to one or more input/output requests directed to at least one data storage region during a first time interval; storing a first cumulative value of the counter modified in response to one or more input/output requests directed to at least one data storage region during the first time interval following the expiration of the first time interval; modifying a value of at least one counter in response to one or more requests directed to the at least one data storage region during a second time interval; storing a second cumulative value of the counter modified in response to one or more requests directed to the at least one data storage region during the second time interval following the expiration of the second time interval; and computing at least one activity index for the at least one data storage region from at least the first cumulative value and the second cumulative value.

Methods and systems for tracking data activity levels

A storage array controller may include a virtual machine manager for managing a storage array application virtual machine and a dedicated multiplexer virtual machine. The storage array application virtual machine and the dedicated multiplexer virtual machine may be communicatively coupled via a plurality of virtual machine manager coupling drivers. The storage array controller may also include a dedicated inter controller link for communicatively coupling the storage array controller with a second storage array controller. The dedicated multiplexer virtual machine may be configured for coupling with a second dedicated multiplexer virtual machine included with the second storage array controller via a device driver communicating across the dedicated inter controller link.

System and apparatus for utilizing a virtual machine to support redundancy in a virtual machine manager pair

A method for detection of hot-swap of disk drives in a storage subsystem devoid of special circuits for such detection and for buffering of bus signals. Typical prior designs utilize special circuits such as disk drive canisters for physically and electronically connecting the disk drives to the storage subsystem. These canisters provided electronic buffering to reduce or eliminate transient (noise and glitch) signals associated with hot-swap drive removal and insertion. In addition, such canisters provided special purpose circuits to inform storage subsystem control modules that a possible insertion or removal occurred by forcing a reset of the interconnection bus in response to detection of such transient signals. The present invention provides for such detection without need for such complex (e.g., costly) special purpose circuits. Specifically, for example in a RAID subsystem using a SCSI interface to interconnect control modules with disk drives, the methods of the present invention detect a possible removal of a disk drive either by periodically polling the SCSI IDs of the RAID subsystem for changes therein or by resetting the SCSI interface in response to errors in processing I/O activity to a removed disk drive. Other methods of the present invention detect insertion of disk drives, either added disk drives or re-inserted disk drives, by periodically polling the SCSI IDs of the RAID subsystem. The methods of the present invention thereby detect hot-swap disk drive insertion and removal without complex (costly) custom circuits therefor.

Software recognition of drive removal or insertion in a storage system

Methods and associated apparatus for automatically synchronizing the operating code between a plurality of controllers. In a first embodiment after the spare controller is swapped into the storage subsystem, if the native controller determines that the spare controller's operating code is incompatible with the native controller's operating code, then the native controller notifies the spare controller that synchronization is required between both controllers. The native controller creates an image of its operating code including configuration parameters, and copies this 'synch info' into a reserved area of cache memory. The spare controller's main CPU utilizes mirroring routines to copy the operating code and configuration parameters into a reserved area of its cache memory. After the transfer is complete, the spare controller's main CPU loads the operating code and configuration parameters into its program memory and resets itself to operate with the modified program memory. In a second embodiment, a co-processor within the spare controller updates the spare controller's operating code by executing a script. The native controller builds the script that includes the operating code, configuration parameters, and instructions to retrieve the operating code and configuration parameters from the native controller's cache memory. The spare controller's co-processor transfers the script to a reserved area in the spare controller's cache memory. The native controller requests the spare controller's co-processor to execute the script which causes the co-processor to retrieve the operating code using mirroring techniques and load the spare controller's program memory with the operating code. The co-processor sends an interrupt to the spare controller's main processor to reset the spare controller.

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Derby, KS, United States of America

Timothy R Snider