International Business Machines Corporation

Matthew Todd Brandyberry

Janet Elizabeth Adkins

Manoj N Kumar

David Jones Craft

Andrew N Solomon

Ninad S Palsule

Vinit Jain

Lance Warren Russell

Joon Chang

Thomas Stanley Mathews

A technique for operating a client node in a clustered file system includes allocating a number of blocks during a first time window and tracking the number of blocks allocated during the first time window. The technique further includes transmitting a block allocation request to a server node of the clustered file system for a number of requested blocks in response to a number of free blocks in a client-side block map reaching a first threshold value. In this case, the number of the requested blocks is based on the number of blocks allocated by the client node during the first time window.

Activity-based block management of a clustered file system

Activity-based block management of a clustered file system using client-side block maps

A method including creating a commit-in-progress context from a copy of a data object in a redirect-on-write file system; and begin storing the commit-in-progress context in a persistent storage device. The method further includes, while storing the commit-in-progress context in the persistent storage device: receiving a notification of a pending modification to the first data object, creating an update-in-progress context from a copy of the commit-in-progress context, and begin applying the modification to the update-in-progress context. The method further includes detecting that a connectivity error has occurred between the commit-in-progress context and the storage device, and in response, identifying whether the commit-in-progress context is successfully stored in the storage device. In response to identifying that the commit-in-progress context is not successfully stored: aborting the storing of the commit-in-progress context, assigning a new commit-in-progress context, and begin storing the new commit-in-progress context.

Merging multiple contexts to manage consistency snapshot errors

In a cluster that distributes fileset management, fileset managers will maintain a free block map and an in-flight block map to allocate blocks to clients writing to a relevant fileset. A fileset manager managing free block allocation for cluster clients that write to a fileset managed by the fileset manager. Since a clustered file system manager manages an initial free block map for the cluster ('cluster free block map'), the clustered file system manager provisions free blocks to fileset managers from the cluster free block map. The fileset manager then allocates free blocks from the provisioned free blocks to cluster clients that write to the fileset managed by the fileset manager.

Distributed free block map for a clustered redirect-on-write file system

In some embodiments, a file management unit located in the operating system detects a write operation that writes the data blocks within the consistency snapshot (in main memory) to the persistent storage. The file management unit can then determine that all transactions have been completed before the write operation begins. In some instances, the file management unit then attempts to write the data blocks within the consistency snapshot to the persistent storage. The file management unit can then receive a notification that the write operation did not successfully write the data blocks from the consistency snapshot to the persistent storage. In some embodiments, the write operation is not successful because there are fewer free data blocks in the persistent storage than needed for writing the data blocks within the consistency snapshot to persistent storage. The file management can then wait a period of time. After the file management unit has waited for a period of time, it can make another attempt to write the data blocks within the consistency snapshot to the persistent storage.

Handling file operations with low persistent storage space

A computer implemented method, apparatus, and computer program product for dynamically loading a module into an application address space. In response to receiving a checkpoint signal by a plurality of threads associated with an application running in a software partition, the plurality of threads rendezvous to a point outside an application text associated with the application. Rendezvousing the plurality of threads suspends execution of application text by the plurality of threads. The application text is moved out of an application address space for the application to form an available application address space. The available application address space is an address space that was occupied by the application text. A software module is moved into the available application address space.

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Austin, TX, United States of America

Matthew Todd Brandyberry