SIRIS, ALTO, and NAS: Getting started with the ShadowSnap Agent



This article describes system requirements for the ShadowSnap Agent.


  • ShadowSnap Agent


System requirements   

  • Windows XP (note: Microsoft no longer issues keys for Windows XP: you may not be able to re-activate installations that use OEM keys)
  • Windows Server 2003 (note: Microsoft no longer issues keys for Windows Server 2003: you may not be able to re-activate installations that use OEM keys)
  • Windows Vista
  • Windows Server 2008 / R2
    • Includes Windows Small Business Server 2011
  • Windows 7
  • Windows 8 / 8.1
  • Windows 10 (only supported up to build 1607)
  • Windows Server 2012 / R2
Supported disk types
  • Basic volumes and disks
  • Windows dynamic disks
  • NTFS filesystems
  • Hardware and software-based RAID implementations
  • Any size disk drive, including disks larger than 2TB
  • MBR boot sectors and GPT partition tables
  • Virtual & physical disks
  • Volumes must be Read/Write
Disk space requirements

Datto recommends maintaining at least 30% free space per protected volume. A minimum of 20% free space per protected volume must be available at all times on the production machine.

Volume Utilization



0 – 70%


Utilization is good.

71 – 80%


Utilization is outside optimal limits. Monitor the volume growth and look at cleaning up unnecessary files and moving non-essential data to other storage.

81 – 100%


Volume is becoming critical. Snapshots will start to fail. Disk queue lengths will increase. Create space.

Memory requirements

Datto recommends a minimum of 1 GB of free RAM for the backup agent. If the agent is reporting errors with less than 1 GB of RAM available, the production machine may require performance tuning or additional resources.

  • Connect the Datto appliance to a Gigabit switch. Datto also recommends connecting protected machines to a Gigabit switch whenever possible.
  • Firewall rules:
    • From the protected machine to the Datto appliance: TCP 3260 (iSCSI port), TCP / UDP 445, TCP / UDP 139
    • From the Datto appliance to the protected machine: TCP 25566. TCP 25566 is live only when the StorageCraft Raw Agent service is enabled and running. Use the netstat command to verify
    • From the protected machine to Internet: TCP 80 outbound to (
    • From the Datto appliance to the Internet: 22, 80, 123, 443 outbound
  • For an in-depth overview of Datto's networking requirements, see the SIRIS, ALTO, and DNAS Networking & Bandwidth Requirements article.
Anti-virus exceptions
  • Set service-level exceptions for the StorageCraft Raw Agent, StorageCraft Shadow Copy Provider, and ShadowProtect services. 
  • Set an application-level exception for the following ShadowSnap Agent executables:
    • raw_agent_svc.exe
    • ShadowProtect.exe
    • ShadowProtectSvc.exe
    • vsnapvss.exe
  • Whitelist the following installation paths: 
    • %SYSTEMROOT%\Program Files\StorageCraft\
    • %SYSTEMROOT\Program Files (x86)\StorageCraft\
  • Verify that you have no other backup software installed on the machine.
Notes  The Datto backup solution relies on shadow storage on the protected machine to complete the backup process successfully. Make sure to disable Shadow Copy processes that are not Datto-related, as these can conflict with Datto backups. For more information, see Disabling and Purging Shadow Copies On Windows Servers.


The current version of ShadowSnap is version 4.0.0, and it works in conjunction with ShadowProtect MSP version 5.0.1. You can download the latest version of the ShadowSnap Agent software at

You can check your protected machine's installed version from the Protect tab of your Datto appliance's GUI.

The ShadowSnap Agent does not automatically update. When an update becomes available, you will need to download and install it manually, and then reboot the protected machine to finalize the installation.


When you install the ShadowSnap agent, you are installing the following services on your Windows machine.

  • StorageCraft Raw Agent: This is the primary service for the webserver, backup jobs, logging, and operation.
  • StorageCraft ShadowCopy Provider: This is the driver that handles the backup engine and VSS interaction. This service is required to quiesce the operating system and take a block-level backup.
  • ShadowProtect Service: This service is required for the ShadowSnap Agent to interact with StorageCraft's ShadowProtect backup software.


We recommend the ShadowSnap Agent if:

  • You have used the ShadowSnap Agent to back up the host in the past.
  • You need to protect a Windows XP OS, Windows 2000 OS, or Windows Server 2003 OS.
  • You need to protect a host which does not and cannot have internet connectivity.

ssflow__1_.pngFigure 1: ShadowSnap Agent data flow (click to enlarge)


The compatibility of this backup solution with any hypervisor environment or operating system not listed in this article is untested and may yield unreliable results. Universal VM Backup may be a viable alternative for backing up virtual machines with operating systems that are not listed as compatible.
  • Backup and restore of deduplicated volumes are unsupported.
  • Before installing the ShadowSnap Agent, disable or remove all other backup software from the production machine. Use a high-level uninstaller that removes all traces of the program after deployment, including registry keys, DLLs, and stray folders. These components can cause conflicts.
  • Before installing the ShadowSnap Agent, ensure that the Volume Shadow Copy Service of the protected Windows machine is Enabled.
  • Acronis software can prevent the installation of the ShadowSnap agent. For any machine that previously had an Acronis product installed, follow the steps in the Removing Acronis article to perform system cleanup.
  • The date and time settings on the protected machine must correspond with the correct time zone in which the Datto appliance device resides.
  • There is a known issue between the Synaptics Touchpad Driver and the VirtualBox Guest Additions software used by the ShadowSnap agent:
    • Older versions of the driver can cause a Blue Screen of Death (BSOD) failure
    • Synaptics Touchpad Driver Version - 9/15/11 is compatible.
    • Subsequent versions can accept the ShadowSnap installer.
  • Due to their mobile nature, Datto does not endorse or support backing up laptops. Laptops must be inside the LAN, and not on a wireless network, to perform backups promptly. Attempts to back up laptops are at your discretion. Due to this consideration, and because of the range of touchpad drivers, custom drivers, and hardware configurations available for both laptops and all-in-one workstations, restoration support for these platforms is 'best-effort' only.
  • The Datto solution is capable of backing up multiple types of disk sector schemes. The process writes an image-based backup to a file that is 512 bytes per physical sector. While rare, certain software that relies on advanced formats, such as 4K, may have issues with the sector size change. Datto recommends performing regular DR tests to ensure that all required applications function as expected in our virtualized environments.
  • The ShadowSnap Agent can only back up volumes that the Windows operating system recognizes as logical, stable volumes. It cannot back up mapped network drives, iSCSI targets without an associated logical volume, or removable drives.
  • Datto supports backup, virtualization, image export, and file restore of supported Windows installations that may be running on Apple hardware via Boot Camp.  Due to dual-boot environment limitations, Datto does not support Bare Metal Restore on dual boot systems. The Datto device will only backup the Windows partition on Boot Camp installations.
  • The backup of deduplicated volumes is untested and may produce inconsistent results. File restore of deduplicated volumes is not possible. The Datto Windows Agent, ShadowSnap Agent, and agentless backup solutions are capable of restoring deduplicated volumes through:


Datto recommends running the following checks on the system you are protecting before installing the ShadowSnap Agent:


Run chkdsk to be sure that all RAIDs and individual disks report back as healthy. Perform necessary disk repairs before deploying any backup agent. Failure to do so may result in backing up corrupted systems and restoration failures.

Disk defragmentation

While Datto can perform backups that are running disk defragmentation, be aware that doing so rearranges data at a block level, and larger backups will result.

Run disk defragmentation before deployment of the agent. 

VSS-aware disk defragmentation programs may allow for smaller backups but are optional.

Windows updates

Download Windows updates, service packs, and any other Microsoft provided updates. After installing these updates, reboot the server. When scheduling your deployment, remember that the 2nd Tuesday of every month is Microsoft's 'Patch Tuesday.'

Virus scan

Run a virus scan before you deploy the Datto backup solution to your production machine.

Event Viewer

Check the target's system and application logs to see if there are any VSS or hardware errors.

Resolve any errors before attempting to install the agent.

Do not install the ShadowSnap Agent on any system currently protected by the Datto Windows Agent, even if the Datto Windows Agent is not present. Installing the ShadowSnap Agent will start a new backup chain for the protected system and will not continue your existing Datto Windows Agent chain.

Before installing the ShadowSnap Agent, disable or remove all other backup software from the production machine. When uninstalling, use a high-level program that eliminates all traces of the incompatible software, including registry keys, DLLs, and stray folders. These components can cause conflicts.

Follow the steps in Installing the ShadowSnap Agent to deploy the agent to your production machine.

Additional Resources

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