What Is Cloud Backup?

How Cloud Backup Stores Your Data Remotely

What is cloud backup? Cloud backup is a method of copying your website or data to a remote storage service run by a provider and reached over the internet. Instead of keeping backups on a disk in the same server room, the copies are uploaded to infrastructure owned by someone else and kept there until you need them.

In practice, a backup tool collects the files and databases, compresses them and sends them to the service. Many services keep the copies in object storage, a design that stores each backup as a named object rather than as part of a traditional file system. Most also keep older versions for a set period, so you can go back to a copy from a previous day or week.

Cloud backup is one way to meet the offsite requirement described in what an offsite backup is. Because the copy lives in a different place from the server, a failure at the original location does not remove it.

Protecting and Paying for Cloud Backups

Once data leaves your server, it must be protected while it is being sent and while it is stored. Good services encrypt the transfer, which is called encryption in transit, and many also encrypt the stored copies, which is called encryption at rest. Both are covered in backup encryption.

Costs usually come from three parts: how much data is stored, how often copies are made, and how much data is downloaded when you restore. The last item is easy to overlook. Some providers charge for data leaving their storage, so a large restore can cost more than months of storage. Compare that restore cost with how long recovery would take before you rely on a service.

Some providers also offer immutable storage, where copies cannot be changed or deleted for a set period. This helps against attacks, which are discussed in immutable backups. Check who holds the encryption keys as well. If the keys are lost, the stored backups cannot be read, even though the data is still there.