Checkpoints for a file system

摘要

Aspects of the subject matter described herein relate to checkpoints for a file system. In aspects, updates to the file system are organized into checkpoint buckets. When a checkpoint is desired, subsequent updates are directed to another checkpoint bucket. After global tables have been updated for updates in the current checkpoint bucket, a logical copy of the global tables is created. This logical copy is stored as part of the checkpoint data. To assist in recovery, a checkpoint manager may wait until all updates of the current checkpoint bucket have been written to storage before writing final checkpoint data to storage. This final checkpoint data may refer to the logical copy of the global tables and include a validation code to verify that the checkpoint data is correct.

主权项

1. A method performed on a hardware computing device, the method comprising:
associating a checkpoint with updates of a plurality of file system objects, where the updates correspond to a transaction, where the file system objects are stored at corresponding first locations on a storage device, and where the updates comprise modified logical copies of at least portions of the file system objects; creating a write plan for writing the updates to the storage device at second locations that are different from the first locations while allowing, in parallel with the creating, other write plans to also be created for subsequent updates that occur subsequent to the associating, where the created write plan specifies that the updates are bound to one another in a context of the transaction, and where the created write plan indicates the second locations; and writing, based on the created write plan and in response to the updates being written to the storage device at the second locations according to the created write plan, checkpoint information to the storage device, where the checkpoint information comprises the created write plan and a checkpoint record.