PROVIDING DATA INTEGRITY IN A NON-RELIABLE STORAGE BEHAVIOR

摘要

In one aspect of the disclosure, progress identifiers (e.g., a plurality of flags) and/or generation numbers are utilized to determine a “correct” non-volatile random access memory (NVRAM) replay source to use during a retried switchover or early switchback. Initially, a switchover sequence is initiated. The switchover sequence includes a replay of logged information to storage devices of an aggregate to ensure data consistency of the aggregate. Progress of the switchover sequence is tracked using the progress identifiers and/or generation numbers. After an interruption during the switchover sequence, switchover is retried or an early switchback is performed. The retried switchover or early switchback decides whether to replay logged information, and, if so, determines an NVRAM replay source to replay logged information from based on states of the progress identifiers and/or comparison of the generation numbers.

主权项

1. A method comprising:
initiating a switchover sequence between one or more nodes of a first cluster and a node of a second cluster of a peer-clustered storage environment, each cluster including one or more nodes coupled to a shared storage fabric that includes an aggregate of storage devices, the switchover sequence initiated in response to a failure of the first cluster, the switchover sequence including a replay of logged information to storage devices of the aggregate to ensure data consistency of the aggregate; tracking progress of the switchover sequence, by the node of the second cluster, using progress identifiers and/or generation numbers; detecting an interruption during the switchover sequence that prevents completion of the switchover sequence; and subsequent to the interruption, retrying switchover or performing an early switch back, wherein the retried switchover or early switchback decides whether to replay logged information and, if so, determines a non-volatile random access memory (NVRAM) replay source to replay logged information from based on states of the progress identifiers and/or comparison of the generation numbers.