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27 Tips & Best Practices for Using the Datto Windows Agent

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Tracy Rock

Director of Marketing @ Invenio IT



In 2017, Datto released the newest version of its Datto Windows Agent as a successor to ShadowSnap. In a video, CEO Austin McChord said the new agent had been in development for the past five years and he praised it for several new enhancements over previous versions:

  • Smaller download
  • Faster, easier installation
  • More compatible with Windows OS versions
  • More efficient compression of data

In this post, we take a closer look at the agent and go over some of the basics for installing it on your machines.

So, what does the Datto Windows Agent do?

In short, the Datto Windows Agent helps facilitate the backup process.

It’s a lightweight piece of software that is installed on each machine that is being backed up—usually your servers, but it could also be individual computers. This is commonly referred to as an “agent-based backup.” (The alternative is known as an “agentless backup,” which does not require software on the protected machines.)

On each protected machine, the agent lives at the kernel level, so that it’s able to detect block-level changes in data. This eliminates the need for a full-system file scan. Thus incremental backups can be taken more efficiently by detecting those block-level changes.

Agent-based vs. agentless backups: which is better?

There is no single right answer to this question. It depends partly on your infrastructure and your business continuity goals.

Since agent-based backups can detect block-level changes in data on each protected machine, they are typically more efficient than agentless backups. On the other hand, an agent will use local computing resources to perform the backup. So if for some reason your server doesn’t have the resources to handle the backup process and other production workloads simultaneously, then there could be performance issues. In general, however, that’s not a problem if your servers are adequate.

Agentless backups are technically also easier to deploy and monitor, particularly in virtual environments where there are lots of changes, because you don’t have to install the software on every machine. Agentless backups operate at the hypervisor level and often must inject temporary executable modules into systems before the backup can occur.

Compression is key

One of the key benefits that McChord singled out when highlighting the new Datto Windows Agent is the data compression, which takes place on protected machines before it’s ushered off to the Datto appliance (i.e. SIRIS or ALTO).

The Datto Windows Agent uses what the company calls “Mercury File Transfer” technology. This technology enables on-the-fly data compression and encryption as the data leaves the machine. This ensures that data is encrypted the moment it leaves the machine on its way to the Datto appliance. It also makes the file transmission dramatically faster in comparison to that of previous versions of ShadowSnap (up to 80 percent faster, according to McChord).

Should you replace ShadowSnap with the new Windows agent?

Nah, that’s probably not necessary. If you are already using the ShadowSnap agent on your protected servers, Datto does not advise making any changes. But for new deployments, yes—go with the new Windows agent.

McChord himself noted, “For all the ShadowSnap agents that you’re currently using, I’d recommend that you stick with them. I’m a firm believer that ‘if it’s not broken, don’t fix it.’”

Datto says there’s no reason to go through the process of swapping out the ShadowSnap agents for the new agent and that ShadowSnap “will continue to work reliably for years.” However, for new installations, the company strongly advises using the new Datto Windows Agent, given all the enhancements mentioned above.

Additionally, you should not install the Windows Agent on any machines that are currently using the ShadowSnap agent (even if the ShadowSnap agent is no longer installed). By installing the Datto Windows Agent, a new backup chain will be started for the protected system. It will not continue your existing ShadowSnap chain.

Getting Started

Okay! Let’s get those backups going.

If you’re just getting started with the new agent, Datto has some handy steps for installing the software and troubleshooting potential issues. We’ll just go over the basics here, so be sure to follow that guidance for more thorough information.

If you haven’t already, you’re going to need to download the agent:

Important first steps, before installing:

  • Make sure the machine is in “good health.” Datto recommends running virus and malware scans, disk defragmentation and a disk health check before installing the agent.
  • Establish Internet connection. The machine needs to be connected to the Internet for the installation to complete and for the duration of the initial agent pairing. Continuous Internet connectivity is recommended.

Select system requirements:

If you have experience with Datto appliances already, then you’re probably already aware of several pre-deployment requirements for your network and operation systems. Here are a few reminders:

  • Windows versions supported: Windows XP Service Pack 3; Windows Server 2003 Service Pack 2; Windows Vista and higher, latest Service Packs recommended
  • The Datto appliance should have a gigabit connection to all relevant network infrastructure.
  • 10% of the volume must be free at time of install; and at least 1GB of RAM must remain free during normal operation for installation and for backups to run.
  • Make sure that no other backup software is currently installed on the machine.
  • Set exceptions within your antivirus software for the Datto Backup Agent and Datto Provider services; application-level: DattoBackupAgent.exe. Be sure to also whitelist the installation path: %PROGRAMFILES%\Datto\Datto Windows Agent\

Some initial configurations and considerations

After installing the agent, you will then be able to configure your backup schedule and other settings based on your business continuity needs. Here are a few things to consider, as recommended by Datto:

  • Be realistic about long-term retention. How far back will you likely need to go to retrieve data? Obviously, longer retention will require more disk space, so it’s a good idea to be practical about how long you retain your oldest backups on-site. Also, keep in mind that Datto offers infinite retention in the cloud with no restrictions on the amount of data.
  • Configure backups based on how the server is used. Critical file servers will clearly need to be backed up often, as that data is constantly in flux. But what about terminal servers that are used primarily for storing configurations? Those servers likely won’t need to be backed up numerous times a day, since nothing is changing.
  • Remove volumes that don’t need to be backed up. Do this before your first backup. If there’s data that simply doesn’t need to be backed up, whether it’s an external storage drive or a USB drive connected to the machine, exclude those from the backup by changing settings in the Advanced options tab.

What about software updates?

They’re automatic. The Datto Windows Agent will automatically download and apply new updates as they become available.

The one exception is driver updates. When a new release includes a driver update, the host system will also need to be updated, so those versions will need to be manually downloaded and installed.

Datto Agents for Mac and Linux

What about IT environments that use a variety of machines, like Mac and Linux? Datto has backup agents for those too, ensuring that you can protect your entire network.

  • Datto Mac Agent: As we recently wrote, Datto was actually the first company to develop a true block-level image backup solution for Mac. Mac’s own built-in backup software, Time Machine, and similar third-party cloning tools, operate at the file level, which is way less efficient.
  • Datto Linux Agent: Released in 2015, the Datto Linux backup agent is unique in how it takes snapshots of production servers without disrupting other server tasks. With the Datto Block Driver, the backup agent creates live snapshots, while keeping the underlying volume running and available. And from then on, the driver tracks incremental changes and “copies the block addresses that change, not the blocks themselves, which is a lot more efficient.”

A word on backing up Windows laptops

It’s pretty standard protocol that all protected devices should be inside your local area network (LAN) and connected directly to it. As such, it’s generally not a good idea to include portable laptops as part of your backup strategy.

Datto does not support backing up laptops due to their mobile nature, and specifically recommends against it. Part of the issue is that backups will not complete in a timely manner when they’re on a wireless network. (Remember: each protected machine should ideally have gigabit connection to the LAN, per Datto’s guidance.) Datto warns that “attempts to back up laptops are at your own discretion.”

That said, if you’re saving data from the laptop to a protected server over a wireless network, you’re fine – and that’s likely the strategy you should be using. Rather than saving files directly to the local machine, you should be saving them to the protected server, where the data can then be encrypted, compressed and transferred to the Datto appliance.

Request a free demo

If you have questions about Datto’s Windows agent, or would like to take a closer look at the data backup systems from Datto, let’s chat! Request a free demo or contact our business continuity experts at Invenio IT today by calling (646) 395-1170 or by emailing

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