Emc IP Holding Company LLC

Michael R Barber

Arieh Don

Yaron Dar

Michael E Specht

Gabriel Hershkovitz

Snapshots are created on replicated storage systems Rand Rin a manner resulting in identical snapshots being generated on Rand R. In response to an instruction to create a snapshot on a storage system (Rand/or R), command-phase write operations (CWOs) are held and data-phase write operations (DWOs) are completed on the storage system before the snapshot is created. Determining that DWOs includes querying processes, and using information, available on the storage system, by which a state of a write operation&#x2014;e.g., whether the write operation is a DWO and when the DWO completes&#x2014;may be determined. A CWO queue may be maintained on the storage system for tracking the status of CWOs. A DWO queue may be maintained on the storage system for tracking DWOs, to determine DWOs when the snapshot is created, and track their processing, including when they are completed.

Creating indentical snapshots

Techniques for memory management may include: allocating, from an allocation pool, buffers for logs used by processing cores; recording messages in the logs for the processing cores; responsive to filling a first buffer included in a first log used to record messages for a first of the plurality of processing cores, allocating a second buffer of the allocation pool for the first log; adding the second buffer to the first list of buffers for the first log; and adding the first buffer, that is included in the first list for the first log, to the allocation pool, wherein after adding the first buffer to the allocation pool, the first buffer is included in the first list of buffers for the first log and also included in the allocation pool. The buffers may be included in a distributed global memory portion of the same computing module as the processing cores.

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Pearland, TX, United States of America

Michael R Barber