How cloud backup actually works

This article explains how cloud backup actually works, what the important distinctions are, and how to know whether your business is genuinely protected.

What cloud backup is, and what it is not

Cloud backup means your data is regularly copied to remote servers hosted in a secure data centre, from which it can be restored in the event of data loss. The key word is copied. A proper backup is a separate, independent copy of your data, not just a sync of what currently exists.

This distinction matters because of how most cloud sync tools work. OneDrive, SharePoint, and Google Drive sync your files across devices and keep them accessible online. But if you delete a file, that deletion syncs too. If ransomware encrypts your files, that encryption propagates across your sync. These tools have retention periods and recycle bins that can help with accidental deletion, but they are not backups in the traditional sense.

A real cloud backup takes a copy of your data at regular intervals, stores it independently of your live environment, and keeps multiple versions over time so you can go back to a point before the problem occurred.

The 3-2-1 rule

The industry standard framework for data protection is known as the 3-2-1 rule. It has been recommended by the National Cyber Security Centre and forms the basis of good backup practice for businesses of all sizes. The principle is straightforward:

3 copies of your data Your live data plus two backups. Not one backup but two, because backups themselves can fail.

2 different storage types The two backups should be stored on different types of media or in different locations. For most SMEs this means one local backup (a network attached storage device or an on site backup appliance) and one cloud backup. This combination gives you fast local recovery for most situations and off site protection for disasters that affect the office itself.

1 copy off site At least one copy of your data should be in a physically separate location, which the cloud copy satisfies. If your office floods, burns, or is burgled, your off site backup is unaffected.

The 3-2-1 rule does not guarantee protection against every scenario, but it eliminates the single points of failure that cause most data loss events. A business following this rule does not lose everything because one device fails, one location is compromised, or one backup is corrupted.

How the backup process actually works

In a well configured backup setup, the process runs automatically and continuously in the background. Here is what it typically looks like:

The backup agent Software installed on your servers, computers, or cloud environment monitors your data and triggers backups according to a schedule. For most businesses this runs at least nightly, with some setups running continuously or every few hours for more critical data.

The initial backup The first time a backup runs, it copies everything: the full dataset. This can take some time depending on how much data you have.

Incremental backups After the initial backup, subsequent runs only copy what has changed since the last backup. This makes daily backups fast and low impact on your network and systems.

Version history Good backup systems keep multiple versions of your data over time, not just the most recent copy. This means you can restore your data to how it looked yesterday, last week, or last month, depending on your retention settings. For ransomware recovery this is critical: if the attack happened three days ago, you need to restore to a point before it occurred, not just the most recent backup which may itself be encrypted.

Encryption in transit and at rest Your data should be encrypted before it leaves your network and stored encrypted in the cloud. This means that even if the backup storage is compromised, the data is unreadable without your encryption key.

Backing up Microsoft 365 specifically

This deserves its own section because it is one of the most common gaps we find in business backup setups.

Microsoft 365 (your email, SharePoint, OneDrive, and Teams data) is not backed up by Microsoft in any way that protects you from data loss. Microsoft protects the infrastructure. They do not protect your data from accidental deletion, malicious deletion by a compromised account, or ransomware.

Microsoft's own retention settings give you a limited recovery window, typically 30 to 93 days depending on the feature and your plan. After that, deleted data is gone permanently. And the retention period resets with every modification, which means a ransomware attack that touches all your files can start that clock running across your entire dataset simultaneously.

A dedicated third party backup solution for Microsoft 365 (one that takes independent copies of your Exchange mailboxes, SharePoint sites, OneDrive folders, and Teams data on a regular schedule) is the only proper answer to this gap.

How do you know your backup is actually working?

The answer to this is uncomfortable for a lot of businesses: you test it. A backup that has not been restored from is not a verified backup. It is a file sitting on a server somewhere that may or may not be complete, may or may not restore correctly, and may or may not cover all the systems you think it covers.

A proper backup solution should include monitoring and alerting so that failed backups are flagged immediately rather than discovered weeks later. It should also include regular restore tests, actually recovering a set of files or a system from the backup and confirming that the result is usable.

If your current IT provider cannot tell you the last time a restore test was performed, that is worth raising.

Want to know if your backup actually covers you?

CT1 Technologies manages cloud backup for businesses across Canterbury and Kent (including Microsoft 365 backup, server backup, and endpoint backup) with monitoring, alerts, and regular restore testing included as standard.

If you are not certain whether what you currently have in place would get you through a serious data loss event, get in touch and we will take a look. We will give you an honest answer rather than a reassuring one.

CT1 Technologies provides managed IT support, cybersecurity, and cloud services to businesses across Canterbury and Kent.