Hewlett Packard Enterprise Development LP

Hewlett-packard Development Company, L.p.

The University of Texas System

Ayman Abouelwafa

Satish Kumar Mopur

Robert Alan Cochran

Sumanesh Samanta

Dinkar Sitaram

Kishore Kumar Muppirala

Murali Vaddagiri

Arif Abdulhusein Merchant

Douglas L Voigt

Mustafa Uysal

Srinivasa D Murthy

Alex Veprinsky

Aswin Jayaraman

James D Preston

Salil Gokhale

Doug Voigt

Erik A Lipps

Narasimha Reddy Annapareddy

Chih-Chieh Chou

Chandrahas Tirumulasetty

Paul Gratz

Christopher David Thompson

Manasij Nandi

Sheridan Clark Kooyers

Sijesh T Balakrishnan

In some examples, an apparatus includes an extender with a first connector to a single-ported input/output (I/O) device, and a second connector to a connection plane connected to a plurality of controllers. The extender includes a multiplexer to selectively connect different controllers of the plurality of controllers to the single-ported I/O device based on a control input comprising a plurality of reset indications from respective controllers of the plurality of controllers. Each reset indication of the plurality of reset indications when asserted causes a reset of the single-ported I/O device, and the plurality of reset indications are to control the multiplexer.

Selective connection of controllers to a single-ported input/output device

In some examples, a system transfers, in a first transfer operation, data of a first storage volume of a first storage location to a second storage volume for a second storage location. Responsive to a completion of the transfer of data of the first storage volume to the second storage volume, the system activates tracking information to track changes to data portions of the second storage volume, the tracking information comprising a plurality of indicators that map to respective different data portions of the second storage volume. As part of a second transfer operation following the first transfer operation, the system transfers changed data indicated by the tracking information from the second storage volume to the first storage volume, without transferring unchanged data in the second storage volume to the first storage volume.

Tracking changes of storage volumes during data transfers

In some examples, for migrating data from a first storage system to a second storage system, a system creates a proxy at the first storage system to direct write requests received at the first storage system to the second storage system, initially sets a cache in the first storage system to a first state in which the cache stores write data for first write requests, and changes a state of the cache from the first state to a second state in which write data for second write requests bypasses the cache and are directed by the proxy to the second storage system.

Data migration using cache state change

In some examples, a system detects recovery, from an unavailable state, of a communication link between a first storage system that includes a first storage volume and a second storage system that includes a second storage volume that is to be a synchronized version of the first storage volume, where while the communication link is in the unavailable state the second storage volume is in an offline state and the first storage volume is in an online state. In response to detecting the recovery of the communication link, the system sends a first tracking metadata for the first storage volume from the first storage system to the second storage system, and in response to receipt of the first tracking metadata at the second storage system that maintains a second tracking metadata for the second storage volume, the system transitions the second storage volume from the offline state to a controlled online state, and initiates a synchronization process to synchronize the second storage volume with the first storage volume.

Storage volume synchronizations responsive to communication link recoveries

Methods, systems, and computer readable media for performing page fault handling are disclosed. According to one method, the method includes: after a translation lookaside buffer (TLB) miss associated with a virtual memory page occurs, identifying, in a page table, a page table entry (PTE) associated with the virtual memory page; determining, using a first indicator in the PTE, that the virtual memory page is not present in a main memory; determining, using a second indicator in the PTE, that the virtual memory page is associated with a valid memory address and that the virtual memory page is capable of using pre-allocated pages; obtaining, from a pre-allocation table, a page frame number associated with a pre-allocated page; and updating the PTE to indicate the page frame number.

Methods, systems, and computer readable media for performing page fault handling

Examples include compressed extent versions. Examples may create an empty target virtual volume tree having a tree structure of a source virtual volume tree of a source storage system, the source virtual volume tree comprising source base and source snapshot virtual volumes, each representing respective versions of a plurality of extents, wherein each of the extents corresponds to a different portion of an address space of the source base virtual volume. Examples may include compressed extent collections, each comprising a compressed representation of multiple populated versions of a single extent from the source base and snapshot virtual volumes, the multiple populated versions compressed relative to one another.

Compressed extent versions

A sub-LUN ownership mapping for multiple storage controllers of a first storage array is generated. The sub-LUN ownership mapping indicates ownership of sub-LUNs by the multiple storage controllers of the first storage array. The sub-LUN ownership mapping is transmitted to a storage controller of a second storage array. A request to align sub-ownership is sent to the storage controller of the second storage array. Ownership is aligned for one or more sub-LUNS for multiple storage controllers of the second storage array.

Storage controller sub-LUN ownership mapping and alignment

An example data storage system includes a first storage array having a first LUN and a second storage array having a second LUN. The first and second storage arrays may implement replication from the first LUN as a primary LUN to the second LUN as a secondary LUN. The first and second LUNs may both be an active target for host write I/O. The second storage array may, in response to receiving from a host a write that is directed to the second LUN, send write data of the write to the first storage for replication array while maintaining a copy of the write data in a fenced portion of a cache of the second storage array. The second storage array may wait to release the copy of the write data to the second LUN until a write acknowledgment is received from the first storage array.

Bidirectional replication

A method generates input/output (IO) commands by plural different applications that execute on a host. The method prioritizes the applications by inserting different classifiers into the IO commands at a host bus adapter (HBA) located in the host. A storage device receives the IO commands and processes the IO commands according to priorities based on the classifiers for the applications.

Prioritizing input/outputs at a host bus adapter

Utilization of the processor modules is monitored. A varying load pattern including at least one of a bursty behavior or an oscillatory behavior of the processor modules is identified. Distribution of logical devices between processor modules is performed.

Moving a logical device between processor modules in response to identifying a varying load pattern

Systems and methods for path selection for application commands are described. To this end, information associated with at least one application command that were processed at least one port of a target device is received. For a subsequent application command, a set of ports of the target device is determined. In one implementation, the set of ports is determined based on information associated with the subsequent application command. Once the set of ports is determined, the subsequent application command is directed to a port selected from the set of ports.

Path selection for application commands

Embodiments include methods, apparatus, and systems for enabling and disabling cache in storage systems. One embodiment includes a method that changes a time period for delaying host requests received at a cache of a storage device and converts the storage device from a cache enabled state to a cache disabled state while the storage device is online.

Enabling and disabling cache in storage systems

Embodiments include methods, apparatus, and systems for replication in storage systems. One embodiment includes a method that uses a target port on a storage array to function as an initiator port on a host in a storage area network (SAN). The target port discovers storage arrays in the SAN and mimics an initiator port to transmit input/output (I/O) requests.

Replication in storage systems using a target port mimicking a host initiator port

In some embodiments, a storage device, comprises a processor, a memory module communicatively connected to the processor, and logic instructions in the memory module which, when executed by the processor, configure the processor to receive a read input/output operation, and configure a prefetch disk data into cache memory in response to a prefetch tag embedded in the read input/output operation.

Growing community of inventors

Folsom, CA, United States of America

Ayman Abouelwafa