Ensuring your backups get off-site is the second most important task a backup administrator is responsible for, second only to ensuring the backups complete in the first place. The “1” in the 3-2-1 rule is that one of your backups needs to be off-site. A copy of the data that you’re protecting should be somewhere other than the data that you’re protecting. Amazingly, however, this fact is often ignored – especially by SMB’s.
The Bad & Ugly of this truth is that there is plenty of evidence to show that many companies and government entities ignore this advice. Almost every natural disaster and terrorist event is accompanied by stories of massive data loss. There were companies that ceased to exist on 9/11 due to data loss. There were prisoners in Texas who had the records of their crimes destroyed by a hurricane. One of the US census was almost completely destroyed by a fire. My favorite story is when I saw a talk at a conference where the speaker was explaining why tapes were bad (long before disk was a viable option for backups). Tapes were bad because he stored them in a box on top of the server that caught fire, and they got destroyed as a result. The really sad thing is he was advocating backing up to a disk system – that he stored next to the server. I really hated to do so, but I had to point out the error in his logic.
The good news is that there are multiple ways to ensure that a copy of your data is off-site. The most common way, unfortunately, is to take the latest backup and ship it off-site via a “man in a van.” While this does satisfy the “1” in the 3-2-1 rule, it ignores the “2.” The “2” says to make sure that your backup is on at least two pieces of media. Sending the only copy of your latest backup off-site does protect you against a disaster, but you are at risk of having a single copy of your backup damaged in some other way, including disasters and magnetic degradation.
Assuming you’re using a traditional data protection system with on-site backup servers, a better way is to copy last night’s backup to another piece of media that is sent off-site. This could be a set of tapes that contain a copy of last nights backups that were stored on disk, or it could be a copy on another disk device created via replication. If you’re using a modern backup appliance setup, the appliance should be capable of copying its backups to another appliance for this purpose. The idea is to have two copies in at least two different locations.
Making sure one of your backups is off-site also applies to SaaS-based data protection products like Druva. Since a copy of your backup is always stored in the cloud, and the cloud always ensures that it stores three physically separate copies via replication, you satisfy all of the elements of the 3-2-1 rule. However, for larger backups needing a quicker restore time, it’s also wise to have a copy stored on-site – for the same reasons mentioned above. This can be accomplished by a local cache appliance that stores recent data on-site – while also ensuring that data is also stored in the cloud.
Whether you’re doing things the old way with traditional backup software, modern backup appliances, or a SaaS solution like Druva, it is crucial to make sure your backups are safely stored off-site. It is also important for certain backups to also be stored on-site. Make sure to take these things into consideration when designing your backup system.