Reducing stable data eviction with synthetic baseline snapshot and eviction state refresh

US11966361B2 · kind B2 · utility

Assignee

• NetApp, Inc. · US

Inventors

• Ajay Pratap Singh Kushwah · San Ramon, US
• Ling Zheng · Sunnyvale, US
• Sharad Jain · Nottingham, GB

Key dates

• Filing date: Nov 29, 2021
• Grant date: Apr 23, 2024
• Expiry date: Nov 29, 2041

Classification

• Technology area (CPC —): General

Abstract

With a forever incremental snapshot configuration and a typical caching policy (e.g., least recently used), a storage appliance may evict stable data blocks of an older snapshot, perhaps unchanged data blocks of the snapshot baseline. If stable data blocks have been evicted, restore of a recent snapshot will suffer the time penalty of downloading the stable blocks for restoring the recent snapshot. Creating synthetic baseline snapshots and refreshing eviction data of stable data blocks can avoid eviction of stable data blocks and reduce the risk of violating a recovery time objective.