Netapp, Inc.

Bhoovaraghan Subramanian

Linda Ann Riedle

Yong Cho

Sandeep Nirmale

William D Dallas

Sangramsinh Pandurang Pawar

Deepan Natesan Seeralan

Sowkoor Sunad Bhandary

Fnu Sahasranshu

Rajesh Rajarman

Fani Jenkins

Systems and methods for performing a fast resynchronization of a mirrored aggregate of a distributed storage system using disk-level cloning are provided. According to one embodiment, responsive to a failure of a disk of a plex of the mirrored aggregate utilized by a high-availability (HA) pair of nodes of a distributed storage system, disk-level clones of the disks of a healthy plex may be created external to the distributed storage system and attached to the degraded HA partner node. After detection of the cloned disks by the degraded HA partner node, mirror protection may be efficiently re-established by assimilating the cloned disks within the failed plex and then resynchronizing the mirrored aggregate by performing a level-1 resync of the failed plex with the healthy plex based on a base file system snapshot of the healthy plex. In this manner, a more time-consuming level-0 resync may be avoided.

Fast resynchronization of a mirrored aggregate using disk-level cloning

Systems and methods for performing a fast resynchronization of a mirrored aggregate of a distributed storage system using disk-level cloning are provided. According to one embodiment, responsive to a failure of a disk of a plex of the mirrored aggregate utilized by a high-availability (HA) pair of nodes of a distributed storage system, disk-level clones of the disks of the healthy plex may be created external to the distributed storage system and attached to the degraded HA partner node. After detection of the cloned disks by the degraded HA partner node, mirror protection may be efficiently re-established by assimilating the cloned disks within the failed plex and then resynchronizing the mirrored aggregate by performing a level-1 resync of the failed plex with the healthy plex based on a base file system snapshot of the healthy plex. In this manner, a more time-consuming level-0 resync may be avoided.

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.

Providing data integrity in a non-reliable storage behavior

Growing community of inventors

Cary, NC, United States of America

Bhoovaraghan Subramanian