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Backup

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A backup is a copy of computer data stored in a different place. This helps people restore their original files after a data loss event. You might lose data if you delete it or if the data becomes broken.

DVD, USB flash drive and external hard drive
DVD, USB flash drive and external hard drive

Backups are a simple way to help with IT disaster recovery. However, not every system can rebuild a whole computer cluster or a database server. A good backup system must contain at least one copy of all the data worth saving. This can require a huge amount of storage space.

There are many ways that data is copied and saved. An incremental backup only saves the data that has changed since a certain time. A full backup saves everything at once to act as a starting point. Some systems use continuous data protection, which is also called CDP. This advanced method saves a copy of every single change instantly. This allows a person to restore data to any specific point in time. Another way is a differential backup, which saves all changes since the last full backup.

Water running on CD-RW - label side
Water running on CD-RW - label side

Experts often use a special system called the 3-2-1 rule. This rule says you should have at least 3 copies of your data. You should also use 2 different types of storage media. This helps if one type of tool fails for a specific reason. Finally, you must keep 1 copy in a remote location. This offsite copy protects your data from fire, theft, or natural disasters like floods. Keeping a copy far away ensures that a disaster at your main site will not destroy everything.

Different tools are used to hold these copies. Magnetic tape was once the most common way to store large amounts of data. It is very fast for reading and writing data in a row. Hard disks are also popular because they are cheap and easy to use. Some hard drives even have shock sensors to help them survive being dropped.

DVD, USB flash drive and external hard drive
DVD, USB flash drive and external hard drive

Optical storage uses lasers to read and write data on discs. These discs are not vulnerable to water, so they might survive a flood.

Understanding backups helps you see how we protect our digital lives. You can think of a backup like a spare key for a house. If you lose your main key, the spare lets you get back inside. Using different media is like having a key and a code for a door. If one fails, you still have the other.

Water running on CD-RW - label side
Water running on CD-RW - label side

Whether using a DVD, a USB drive, or a cloud service, backups keep our information safe.

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Water running on CD-RW - label side.jpg
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