Netapp, Inc.

International Business Machines Corporation

Paul Anthony Powell

Akhil Kaushik

Ching-Yuk Paul Ngan

Srikumar Natarajan

Archna Kalra Johnson

Madhumita Vohra

One or more techniques and/or computing devices are provided for implementing synchronous replication. For example, a synchronous replication relationship may be established between a first storage controller hosting local storage and a second storage controller hosting remote storage (e.g., replication may be specified at a file, logical unit number (LUN), or any other level of granularity). Data operations and offloaded operations may be implemented in parallel upon the local storage and the remote storage. Error handling operations may be implemented upon the local storage and implement in parallel as a best effort on the remote storage, and a reconciliation may be performed to identify any data divergence from the best effort parallel implementation. Storage area network (SAN) operations may be implemented upon the local storage, and upon local completion may be remotely implemented upon the remote storage.

Synchronous replication for storage

Synchronous replication for storage area network protocol storage

Updating data in a distributed system, in which a data coordinator receives a proposed change to a data element, locks the data element, and sends an invalidation command to nodes in the distributed system. If all nodes acknowledge the invalidation command, the data coordinator updates the data element locally and unlocks the data element. If not all nodes acknowledge the invalidation command, the data coordinator terminates the proposed change and unlocks the data element. Each node that invalidated the data element requests the data element. The data coordinator returns its current value. If the value is changed, all nodes request and receive the update. If a node did not invalidate, it will not request an update, but the value will not have changed so all requesting nodes receive the previous value. Thus, all nodes have the same value for the data element and consistency is maintained throughout the system.

Data updates in distributed system with data coherency

An operating system on a computer system can comprise a user space, which can comprise a persistent data store, and a kernel space, which can be extended by loading kernel modules. As provided herein, the kernel space can utilize kernel designated electronically addressed non-volatile memory (e.g., flash memory) to cache data from the user space persistent store, for example, upon a boot event. The kernel space can further comprise a cache controller that can be used to populate the kernel electronically addressed non-volatile memory with kernel in-memory data caches that comprise user space persistently stored data. In one embodiment, the kernel space can further comprise kernel designated volatile main memory (e.g., RAM), which can be used in conjunction with the kernel electronically addressed non-volatile memory to cache user space persistently stored data. In this way, kernel modules may access user space persistent store data from the RAM and/or electronically addressed non-volatile kernel cache.

Electronically addressed non-volatile memory-based kernel data cache

A method, system, and program product for enabling selection of appropriate, available resources for a hardware component of a data processing system during system boot via a read only medium. The method comprises various steps including first initiating a boot process from the read only medium on the data processing system. The type of hardware component is then detected and, responsive to the detection of a specific component type, an object of a symlink file located on RAM is dynamically set to reflect the particular resource required for optimal operation of the hardware component. A symlink file located on the read only medium points to and triggers the activation of the symlink file on RAM. The first symlink file on RAM points to and selects the particular resource set as its object from among multiple available resources located on the read only medium. The selected resource is utilized to support the hardware component during operation of the data processing system.

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Holly Springs, NC, United States of America

Paul Anthony Powell