Commvault Systems, Inc.
OPTIMIZING THE RESTORATION OF DEDUPLICATED DATA STORED IN MULTI-NODE REPLICATED FILE SYSTEMS

Abstract:

Techniques disclosed herein are well suited to restoring deduplicated backup data from cloud-based storage and from multi-node replicated files systems, and they also improve performance in more traditional data storage technologies. Pre-restore steps include analysis of deduplication indexes to identify data segments that are stored consecutively on storage media. Reading data in aggregate runs of consecutively stored data segments reduces interactions with storage media that hosts the deduplicated data and speeds up retrieval. Parallel reads from multiple storage devices in multi-node replicated file systems also speed up retrieval. An illustrative enhanced media agent pre-fetches data (stored in deduplicated form) in anticipation of read requests that are expected in the restore operation. The pre-fetched data is temporarily stored locally at the media agent, which is responsible for interfacing with storage media and is further responsible for orchestrating the disclosed techniques within an illustrative data storage management system.