Disaster Recovery & Backup
Backup strategies, RPO, RTO, failover, high availability, multi-region deployments, troubleshooting DR scenarios
1What is RPO (Recovery Point Objective) in the context of disaster recovery?
What is RPO (Recovery Point Objective) in the context of disaster recovery?
답변
RPO defines the maximum amount of data an organization can afford to lose during a disaster, typically expressed in minutes or hours. An RPO of 1 hour means backups must be performed at least hourly to limit data loss to that time window. Strategies to achieve low RPO include continuous backups (CDC), frequent snapshots, or synchronous replication for near-zero RPO in critical systems.
2What does RTO (Recovery Time Objective) represent in a DR strategy?
What does RTO (Recovery Time Objective) represent in a DR strategy?
답변
RTO represents the maximum acceptable time to restore a service after an incident before business impact becomes unacceptable. For example, an RTO of 4 hours means the service must be restored within this timeframe. RTO directly influences DR architecture choices: short RTO requires solutions like hot standby or active-active, while longer RTO can use less expensive approaches like pilot light or cold backup.
3What is the main difference between a full backup and an incremental backup?
What is the main difference between a full backup and an incremental backup?
답변
A full backup copies all data at each execution, while an incremental backup only saves data modified since the last backup (full or incremental). Incremental backups are faster and consume less space, but restoration is more complex as it requires the last full backup plus all incrementals. A common strategy combines weekly full backups with daily incrementals to balance performance and restoration ease.
What is a snapshot in the context of backup strategies?
What is the difference between active-active and active-passive architecture for high availability?
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