备份的3-2-1原则

• 3: You must have at least three copies of your data: the original production data and two backups.
• 至少3份数据，一个生产，两个备份
• 2: You must use at least two different types of media to store the copies of your data, for example, local disk and cloud.
• 至少两种不同存储介质
• 1: You must keep at least one backup offsite, for example, in the cloud or in a remote site.
• 至少一个离线站点