In the IT world, some rules are always changing. It’s good to remember, however, that some rules are timeless because they still make A LOT of sense! The 3-2-1 backup rule is a great example.
The 3-2-1 backup rule can help you overcome nearly any failure scenario if you follow it.
The 3-2-1 backup rule implies that you should:
3 copies of your data because it is important, one that is live and in use, another copy on your network so if something is deleted you can get it back quickly and another in archival format – either on tape or using a disk/cloud based solution.
2 different types of media because if one type fails you have the other type to fall back on. It has been known for companies to use the same media at both sites such as the same manufactures SAN for live and backup data and then a common failure, firmware or bug effect both sites.
1 backup off site because the site/data location might not be there in the morning. This could be the office, data centre or cloud (Dropbox, AWS, Azure, Sharepoint etc). Your data and systems are the company’s life blood and the ability to recover your data back due to loss from accidental, malicious deletion or systems failure from a different location back to a place where is can be accessed again may be the difference between the company’s survival or not. Ideally this offsite data is Air-Gapped between the live site and offsite location. By Air-Gapped we mean ensuring something like ransomware cannot cross from your live site to your offsite backup and corrupt both sites rendering your ability to recover useless.