Why agentless backup is the Holy Grail for disaster recovery

Disaster must be defended against
Disaster must be defended against

Agentless backup is the latest buzzword in disaster recovery (DR) and business continuity (BC), but how much do we really know about it, or what it means for organisations using the system?

Most people probably know that agents are the small applications installed on a server to perform a particular function. For backup, the agent is installed onto the host server the system administrator wants to back up. Agentless backup is, as its name suggests, backup without the use of such an agent.

In an effort to distinguish themselves from their rivals, several backup and recovery vendors claim to provide agentless backup. In many instances, however, these vendors inject an agent at the beginning of the process and remove it before the backup finishes in order to achieve application consistency. Strictly speaking, they aren't providing agentless backup because they are still using an agent in parts of the process.

Why do we need agentless backup?

While agent-based solutions are effective and proven, there are a number of reasons why organisations might seek to move away from agent-based backup. Some agent-based solutions can be weak from a security point of view, and expensive. Adding agents increases the amount of software organisations have to manage. Agents can also interfere with the processing power of core applications when they are installed.

Even in a normal sized environment, agent management can be a complex process as IT administrators deal with different agents on different operating systems. The growing number of software packages running on a host server could prove to be a further complication.

By removing the agent, backup solutions can bypass the process of agent management, while ensuing a faultless backup.

The benefits of agentless backup

Organisations are looking to agentless backup for an easy to manage backup solution that can provide benefits for DR and BC including:

  • Easy installation and support: Agentless backup doesn't require a reboot of your system during the installation process
  • One piece of software to manage: By only having one piece of software to manage, agentless backup can work faster and more efficiently in comparison to agent-based backup
  • Less time consuming: Agentless backup can upgrade itself. Often hundreds or even thousands of systems need to be backed up so the process becomes less time consuming for IT managers
  • Compliance: Some organisations cannot inject agents due to regulatory requirements. Where data handling cannot be modified from beginning to end, an agentless solution allows for compliance during backup
  • Consistency and recoverability: Agents can interfere with the processing power of core applications of the machines they are installed on. With agentless backup, remote sites can easily implement and maintain data backup programmes
  • Cost effective: Agentless solutions eliminate the costs associated with agent-based backup. Organisations can save money on maintenance and operating costs


Faced with a variety of ways of backing up critical data, organisations need to consider a number of factors when choosing the correct backup including cost, simplicity and consistency. Given a choice between agent-based or truly agentless solutions, businesses should be able to make an informed decision based on their management, CPU overhead and compliance needs.

Truly agentless backup is not only easy to use but also requires no injection or removal of an agent during the process at all. Designed to bring a new kind of protection to the market, agentless backup has the potential to provide users with cost effective and rapid DR.

Agent-based backup works well today but, given the additional benefits it can deliver, it's easy to see why agentless backup is becoming the Holy Grail for DR and BC vendors. Few have achieved it so far.

  • Gabriel Gambill is Senior Systems Engineer for Quorum in EMEA