Choosing home backup server depends upon the amount of storage that you need and whether that storage needs to be accessible by many devices.
If you are simply backing up your local computer then a USB attached storage device should be sufficient for your needs. If you’re backing up more than one computer or need to share the files with more than one device then you want to look at Network Accessible Storage. Your next consideration is whether or not you want the storage to be redundant or safe in case a drive fails.
Redundant RAID File Storage
Redundant storage solutions allow you to have more than one drive save your information in such a way that if one Dr fails the other drives will automatically have copies of the Lost information.
RAID Storage comes in a few different types of formats. You can directly mirror a drive which means that you have two drives with the exact same information or you can select raid 5 and have a stripe set which means a small amount of information about the contents of all drives is stored on each drive. The benefit of having a mirrored copy is that all of the information is accessible for reading at the same time however when you write a file it takes twice as long. The benefits of having a striped set is that each drive can fail independently and the rest of the drives will take up the slack. If one drive fails in a mirror set or in a striped set you must replace that drive as soon as possible. The information that was lost will then be copied back to the new drive.
The most important thing to understand is that a stripe set raid array could have larger drive storage.
When setting up a RAID solution you can do so by installing a card in your current computer or server or you can buy a free standing raid server that will hold your drives.
If your needs are much smaller then I suggest you simply purchase two external hard drives and use a file copy tool like RichCopy to mirror the files between the drives while you work.
Connecting your storage to your network
NAS stands for network accessible storage. In the easiest method you can simply select a RAID storage solution and then connect this device to a network portal such as Wi-Fi router.
When setting up network accessible storage it is important to factor in security. Many levels of user permissions should be used to secure your data. You should also restrict access from the internet if you have any information on your storage server that you want to keep private. Server security is there a very difficult process even for professionals if you are in doubt of your capabilities you should set up a separate network within your home that is detached completely from the internet. This is important for many people who are using large storage systems for multi media in their home.
Look no one is perfect at security but you should at least take the steps to learn about this requirement and do your best to make sure you get it done.
Final note
My personal preference is to set up a separate network for my backups and multimedia storage and not connect this storage to the internet at all. I have worked with computers professionally for more than a decade and I have found that even the most secure solutions can be compromised by one missed security update or one inappropriate policy setting.
It is more important that you protect your data than share it with your friends. I find the idea of wanting to access your multimedia from your work or school or when you are on the road to be foolish. When you are out of the home find other things to do than watching your television. If you have your phone you will always have access to internet-accessible media.
When selecting a storage solution raid becomes important once you reach the size of an external hard drive. At this time 5 terabytes is the average size of an external hard drive. If you expect your needs to grow double or triple this size you will need a storage solution that you can depend on.
Although you can purchase unlimited online storage from a variety of providers you should not trust this solution with your more secure data. I am sure that solution providers will take exception to my suggestion that their storage is insecure but this is a fact that can be backed up by security websites both governmental and private. Cloud storage is insecure for most customers and does not pass standards necessary for secure storage required by banks. If banks do not trust the storage solutions which are of a higher security level than personal unlimited cloud storage you should not trust this solution for your data even if you encrypt the data before you upload it.
These are my personal feelings as a professional this is not to say that I have detailed knowledge of each storage solution available however do your own homework and read about the solutions before you select them.