Continuous Data Protection (CDP)

CDP compared against other backup technologies

While there are a lot of different advantages and specifications that CDP can offer as an alternative to other backup technologies, there’s still a potential catch if you want to replace all other traditional backup types with CDP.

The problem is the location of your future backup. You may still be exposed and left without all of your data if you’re keeping all of your backups on-premise – at the same location as your main server. Offsite backup storages are crucial to prevent that kind of possibility entirely.

When it comes to comparing CDP and snapshot-based backup technologies, there is usually a clear winner between the two, and it’s CDP. There are two main reasons for that – storage space savings and intervals between backups.

First of all, the difference in storage space taken between snapshot-based backups and CDP ones is quite impressive – up to two times less disk space is taken with a regular CDP backup when compared to a snapshot backup. There’s also the fact that CDP can perform backups with remarkably small intervals - like several seconds - but snapshots are typically not less than an hour interval.

On the other hand, the difference between CDP and near-continuous backup is not as clear. Both can offer instant data recovery and both can roll back to a specific point in time in case there’s a need for that.

The main difference between them is in the RPOs that they can offer. While CDP can easily offer a recovery point objective of practically 0, a near-continuous one aligns with your shortest backup interval, which is typically at one hour mark.

One backup type left is mirror backup, and this one has a lot of differences with CDP, too. The main difference is that a mirror backup creates an exact copy of all of the files within the selected folders and replicates it to a separate offsite storage space to have an alternative in case any disaster happens.

This storage technology on its own is relatively outdated and was mostly popular before cloud backups, and when continuous data protection was too much money and effort to implement at the time.

• Snapshot creation puts additional workload on your system. This may be taxing on your whole environment, especially on virtual machines that are resource-efficient and typically operate at 80% CPU usage. By contrast, most physical servers operate at 10-30% CPU usage.

Advanced CDP Solutions with Bacula Enterprise

As opposed to conventional backup solutions, Bacula Enterprise CDP does not require regular snapshots of your entire system. It saves only the bits of data that have changed, which results in seamless backups that are not taxing on your resources and have no significant impact on your system’s operational workload. This approach enables you to perform granular recovery of only those bits of data that you actually need to restore. Granular restore can be crucial for predominantly virtual environments, where recovery point objectives (RPOs) are tight and recovery time objectives (RTOs) are very short.

CDP Solutions Availability for Bacula Clients

Continuous Data Protection is available at no extra cost for all Bacula Enterprise customers and can be used on client computers and virtual machines based on Windows, Linux, Mac OS, or any other supported platforms.

Use Case of Continuous Backup

A medium-sized hosting provider operating in Greece and the Balkan states needed an always up-to-date backup, as well as the ability to dial back to the right moment in time before an event – such as data corruption – had happened. Five years ago, their hosting environment consisted of approximately 70% physical servers and 30% virtual machines. The company had been using traditional backup solution and methods that provided full and differential backups. This had initially been enough for its needs. Now, however, the company’s technicians were running out of time to complete regular backups.

In addition, the company’s difficulties were being exacerbated by a growth in data volume. As the company was growing successfully, this data growth was expected to continue well into the future, and any solution would have to be ‘future proof’ with this aspect in mind.

It became clear that the company needed to move to a solution that was modern, efficient and fast, and that would allow the user or administrator to restore data to any point in time. After further research, the company realized it would be highly advantageous to employ a true CDP software solution that would detect when a file was changed and copy it into a local spool area. The company needed files to be available for immediate recovery locally, and the ability to automatically capture and track data modifications, saving every version of user-created data locally or at a target repository. However, in recent years, as the company moved towards virtual infrastructure, the proportion reversed: now their environment is mostly made up of virtual machines and servers (78%) with physical servers making only 22%.

As conventional backup and restore operations are highly resource - and time-consuming, the organization started looking for a CDP system that they could use instead or together with their existing backup infrastructure.

After a careful comparison of all alternative CDP solutions, the company decided to use Bacula Enterprise, benefiting from its built-in Continuous Data Protection capability. Bacula closely integrates highly effective CDP into a comprehensive, enterprise-grade backup and recovery environment, which presents an advantage to system administrators and users. Bacula’s approach is to be as platform-agnostic as possible, with no particular file system requirements. Among the many advantages of this philosophy, one of them is the ability to significantly reduce the need to rely on snapshots.