 Welcome to the data management video series from the University of Wisconsin Milwaukee Libraries. I'm Kristen Briney. I am the data services librarian, which means I am your campus expert on all things data management. Today, I want to talk to you a little bit about one of my favorite recommendations for data management, and that is the 321 Rule. And the 321 Rule is a rule of thumb to make sure you have adequate storage and backups. And this is data management at its most basic, because you want to make sure your data are protected from loss. And you can do that by having enough storage and backups. So the 321 Rule says you should have three copies of your data in two different locations on more than one type of storage medium. Let's break that down a little bit more. So three copies of your data. There is a saying in librarianship called lots of copies keep stuff safe. And the idea is that the more copies of your data you have, the more likely you'll end up with your data if something happens at the end of the day. So you want lots of copies of your data, but you want a manageable amount of copies of your data. So three is actually a really nice compromise between having enough copies and having too many copies. So three copies of your data is what you're shooting for. The second part of the 321 Rule says that you should have your data in two different locations. And this is actually one of the most important parts of the 321 Rule, because a lot of disasters with your data happen locally. For example, a natural disaster comes through and something happens to your data. Or there's a fire in your building or your laptop is stolen. All those things happen locally. And if you don't have an offsite copy of your data, you might lose all of your data. There's a really good story or a bad story about a graduate student who did have a nice backup copy of his data, but he stored it on an external hard drive that was sitting right next to his laptop. And when his laptop was stolen, his hard drive was stolen. And he lost four years of data, and just gigabytes and gigabytes of data. And this was a student who was going for his PhD, but didn't actually get his PhD because he lost his data. It wasn't worth retaking any of that data. He left with a master's. So it's really important to remember nothing else from this video. Have an offsite copy of your data just in case. The last part of the 321 Rule is storing your data on multiple types of storage, more than one type of media. And this is really important because you want to spread your risk around. So every type of storage comes with some risk. For example, hard drives have an average lifespan of six years. Now cloud storage usually lasts longer than that, but when you put your data in the cloud, you're making your data dependent on a company's business model. So if that business folds, or if they change their services, your data could be at risk. So if you have your data only in the cloud, make sure you have a copy of your data on some other type of storage. It's really important. So that's the 321 Rule. Three copies of your data in two different locations on more than one type of storage. And this is a really basic thing you can do to improve your data management because you're going to make your data safer from loss. And that is really data management at its most basic, taking care of your data. So if you're trying to figure out how to follow the 321 Rule, just try to take advantage of whatever storage options you have available to you. It doesn't have to be difficult. You don't have to go out and buy a bunch of new storage devices. Just try to make the most of what you have. If you end up with your laptop, your data stored on a local department server, and you put a third copy of your data in the cloud, all of a sudden you satisfy the 321 Rule. So I hope you use this to make your data a little bit safer, to manage your data a little bit better. It's really a great starting point if you've never done data management before. So it's the 321 Rule, three copies of your data in two different locations on more than one type of storage.