Staged Restore Decremental Backup Chain Downtime

The patent applies preliminary action by restoring a first backup (base backup or earlier decremental backup) to the restore storage in advance, before the source storage becomes unavailable. This staged restore approach prepares the restore storage proactively, so that when the source storage fails, only the remaining decremental backups need to be applied, significantly reducing the actual downtime compared to waiting until failure occurs to begin restoration.

The patent applies segmentation by dividing the backup process into a base backup and multiple decremental backups. Instead of completing one large base backup that takes hours or days, the backup is segmented into smaller units that can be created and applied incrementally. The base backup captures initial state, and subsequent decremental backups capture changes, allowing the restore process to start with the base backup and apply smaller decremental updates over time, reducing the impact of large backup operations.

The patent applies inversion by reversing the traditional decremental backup application order. Instead of requiring all subsequent decremental backups to be applied in sequence from the most recent backward, the system allows restoration by applying decremental backups in a staged manner from the base backup forward, similar to incremental backup logic. This inverted approach to decremental backup application enables staged restore convenience while maintaining the space efficiency benefits of decremental backups.