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The Truth about All Datto SIRIS Models for BCDR

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Dale Shulmistra

Data Protection Specialist @ Invenio IT


Datto SIRIS Models

The Datto SIRIS is considered one of the industry’s best business continuity and disaster recovery (BCDR) solutions. But it’s not a one-size-fits-all device. There are multiple Datto SIRIS models to choose from, allowing you to select the right fit for your infrastructure and business continuity needs.

In this post, we look at some of the key differences between these models and how they stack up with other Datto solutions.

 What is the Datto SIRIS and why is it essential for BCDR?

The Datto SIRIS is an all-in-one solution for data backup, business continuity and disaster recovery. It provides total data protection with a dedicated on-site backup device that replicates backups to the immutable Datto Cloud. It protects physical, virtual and cloud infrastructures running on Windows, Mac or Linux.

Let’s start with a quick overview of the data-protection capabilities built into all Datto SIRIS models.

The foundation of the Datto SIRIS is a physical BDR appliance that allows for fast, resilient backups that can be restored and virtualized in minutes, from virtually anywhere.

  • Image-based backups: Each backup is a fully constructed virtual machine that can be booted up almost instantly from the SIRIS device or from the Datto Cloud.
  • 5-minute RPO: Datto’s patented Inverse Chain Technology eliminates the dependence on previous snapshots, allowing for more granular backups (as often as every five minutes), without having to reconstruct the backup.
  • Fast, iron-clad recovery: The most commonly occurring problems in conventional backup chains are eliminated completely with Inverse Chain Technology, resulting in a more resilient backup and no surprises during recovery.
  • Virtualize from anywhere: Backups can be virtualized with a few clicks, allowing nearly uninterrupted access to critical files and applications.
  • Cloud replication: All protected data is replicated to the immutable Datto Cloud. Backups are stored in at least two secure, geographically diverse data centers for greater redundancy.
  • End-to-end encryption: All data is encrypted (AES-256) as it’s in transit and as it resides in the cloud.

Datto markets the SIRIS as “the first fully featured total data protection platform delivered in one integrated package.” We’ll dig into more of its innovative features below, but first, let’s look at some of the differences between the various Datto SIRIS models available.

Datto SIRIS Models Compared

What is the Datto SIRIS 5?

The SIRIS 5 is the latest-generation SIRIS, available in several models to fit the needs of both small, medium and large organizations. It’s Datto’s top-of-the-line BDR device, offering enterprise-level data protection at a value that makes sense for smaller businesses, too.

The SIRIS 5 is designed to protect physical, virtual and cloud infrastructure running on Windows, Mac or Linux. With the fast recovery process and virtualization capabilities mentioned above, admins can spin up lost servers in a matter of seconds, without the need for additional tools.

All SIRIS 5 models are powered with Intel Xeon processors and equipped with SSD Flash O/S drives, ranging from 256GGB NVMe to480 SATA SSD. Storage capacity and RAM vary by model, so here’s a quick breakdown of the different levels available:

Datto SIRIS Comparison

Note: If the SIRIS 5 seems like “too much” for your continuity needs, check out the Datto ALTO. The Datto ALTO offers many of the same features as the SIRIS 5, but in a package that makes more sense for small businesses.

SIRIS 5X Series

What is the SIRIS 5X (S5X)?

The Datto SIRIS X is a Mini PC version of the SIRIS 5, built with all-Flash storage for greater speed and performance. It is designed for smaller businesses and has a backup storage capacity of 2TB.

The SIRIS X series devices have redefined the industry’s performance standards by incorporating blazingly fast solid-state drives (SSD). Datto says that speeds are unrivaled in the industry, and we don’t doubt it. Faster drives translate into faster backups, faster recoveries and seamless virtualizations that let you run your critical applications without a loss in performance.

All SIRIS X devices offer the full functionality of the SIRIS 5. But instead of using traditional, spinning hard disk drives, the X series stores data on chips. That means no moving parts, which are inherently prone to mechanical failure over time.

The SIRIS 5 X (S5X) is currently available in a 2TB Mini PC option. Here’s a quick snapshot of the specs as they compare to the larger SIRIS devices:

  • Mini PC
  • NVMe SSD
  • Dedicated OS drive
  • CPU: Intel Core i3-10100T processor
  • RAM: 16GB DDR4
  • 1G Base-T NIC

Previous iterations of the Mini PC SIRIS X were available in 1TB, 2TB and 4TB options, so it’s possible these storage options will be introduced at a later time. Datto also previously offered Enterprise-level versions of the SIRIS 4X in 2U rackmount devices with storage capacities up to 48TB. However, with the launch of SIRIS 5, Datto introduced a new strategy of consolidating its SIRIS models into a smaller product line to provide greater simplicity to MSPs and their clients. Altogether, SIRIS 5 is available in 13 SKUs, down from 25 with the SIRIS 4.

Virtual SIRIS (vSIRIS)

What is the Datto vSIRIS?

The Datto Virtual SIRIS (vSIRIS) is a software-only, virtual deployment of SIRIS. It offers the same core functionality as the physical SIRIS, but it runs in a virtual machine (VM) via VMware or Hyper V on existing hardware.

Datto has marketed the virtual device as “the easiest way to protect your data, regardless of infrastructure.” It protects both virtual and physical environments and has local storage options ranging from 500GB to 60TB.

Virtual SIRIS supports virtual environments on VMware vSphere, Microsoft Hyper-V and Citrix XenServer.

One key difference between the SIRIS 5 and the Virtual SIRIS is that Virtual allows an administrator to run the device as a virtual guest. VMs can be spun up instantly from the Datto Cloud—including even your oldest “archived” recovered points. Or, they can be spun up directly on the local device, even in the absence of Internet connectivity.

Benefits of deploying SIRIS as a virtual appliance:

  • Quick remote deployment
  • Can be deployed on existing hardware / virtual environments
  • Simpler software-only deployment
  • Support a wide variety of custom configurations

For the managed-service providers that deploy vSIRIS for their clients, the virtual model is attractive because it requires less administrative overhead. In essence, it makes the management of hundreds of clients as easy as it is for just 1.

Virtual SIRIS models are denoted by SV in the model numbers, which range from SV1 to SV100. Each model has its own requirements for performance and resources, but as a rule of thumb, larger deployments (with greater storage capacities) require more CPU and RAM.

For example:

  • The base model, SV1, requires a minimum of 16 GB RAM and 4 CPU sockets (x1 cores) attached to the Virtual SIRIS.
  • The top-end model, SV100, requires at least 256 GB RAM and 12 CPU sockets (x1 cores).

SIRIS Imaged

What is SIRIS Imaged?

SIRIS Imaged is a full-featured, software-only deployment of SIRIS 5 that is deployed on your existing hardware.

With SIRIS Imaged, Datto lets you repurpose existing BDR appliances or other hardware into a fully functional SIRIS 5 device. Simply insert and boot the USB drive and voila! You’ve got all the functionality of Datto SIRIS within your current hardware. After booting the USB drive, you simply follow the on-screen instructions to complete the SIRIS 5 image and start protecting your infrastructure immediately.

Hardware and resource requirements for SIRIS Imaged include:

  • Minimum quad-core 64-bit processor (Datto prefers Intel)
  • 1GbE DHCP-enabled Internet connectivity
  • Operating system: at least 120 GB SSD (SATA or NVMe). 60 GB would be allocated to the OS partition
  • Pool Drives: minimum of two drives (either HDD or SSD, has to be the same type, same model preferred), at least 1TB in capacity

The minimum RAM requirements are dependent on the storage capacity of the local hardware. SIRIS Imaged models are denoted by SI in the model numbers, ranging from SI1 to SI60. The numerals represent the storage capacities. SV1 denotes a storage capacity of 1TB, which requires 4 CPU cores and 32GB RAM. On the top end, the SI60 requires 256GB RAM and 36 CPU cores for a storage capacity of 60TB.

SIRIS Private

What is SIRIS Private?

Datto SIRIS Private is private-cloud deployment of the Datto SIRIS. It is deployed as two Datto SIRIS devices to create a self-contained private cloud, so that backups are stored on company-owned hardware, rather than on Datto’s cloud.

SIRIS Private is an ideal solution for organizations that must adhere to strict requirements for how their data is stored. In industries like healthcare and financial services, certain rules prohibit the storage of data on public clouds, particularly on shared servers that contain other organizations’ data.

Datto provided the solution in 2019 by enabling two Datto SIRIS devices to be seamlessly integrated. Like the conventional SIRIS, backups are stored on a local SIRIS device. But they are replicated to a secondary SIRIS, typically deployed off-site, creating a private cloud.

Deploying SIRIS Private requires:

  • One SIRIS to serve as the “source” device for performing backups of the protected machine(s).
  • A second SIRIS to act as the “target” device to store replicated copies of the source device’s backups.

Otherwise, SIRIS Private provides the full feature set and functionality of the SIRIS 5. But by creating a self-contained private cloud, it helps organizations stay in compliance with data regulations.

Older Generations & Discontinued SIRIS Models

If you want to take a stroll down memory lane, you can still access a wealth of information online on the SIRIS 5’s predecessors (including even the original SIRIS). Here’s a quick overview of each.


On a fundamental level, the Datto SIRIS 4 (and its predecessors) offered much of the same functionality as the SIRIS 5 does today, minus some of the features and power.

Announced at the 2019 DattoCon – Datto’s annual conference for managed-service providers – SIRIS 4 introduced an overhaul of hardware to make backup processes even faster. Most notably, the SIRIS was upgraded with new high-powered processors from Intel: the Skylake and Cascade Lake CPUs. Both processors featured additional cores and a dedicated write cache (SLOG).

The increase in processor power helped to dramatically improve the SIRIS’s backup virtualization capabilities. Virtualization speed was 2 times faster than that of SIRIS 3. Plus, it allowed more agents to be virtualized per device. So for example, if businesses were recovering from a widespread ransomware attack, SIRIS 4 enabled them to virtualize multiple protected machines to access more applications and data.


The SIRIS 3 was released in June 2016, introducing new software, OS upgrades and new features. It ushered SIRIS into a new era of business continuity and disaster recovery, vastly improving upon the performance of SIRIS 2.

Most notably, SIRIS 3 moved from Cherokee to Apache Web Services. Datto also upgraded the PHP infrastructure and OS (from Ubantu 12.04 to 16.04), which improved security and reliability. The hypervisor was swapped out from VirtualBox to KVM, which allowed greater flexibility and increased performance for Instant Virtualization. Finally, SIRIS’s Bare Metal Restore process was improved to deliver higher success rates and greater compatibility with other hardware.


The Datto SIRIS 2 was announced in 2014, offering storage capacities of 500GB to 60TB, depending on the model (Business, Professional, Enterprise).

In a brochure, Datto marketed the SIRIS 2 as “the only backup, recovery, and business continuity solution to offer instant local and off-site virtualization, Screenshot Backup Verification™, and Backup Insights™ all from one simple management interface.” (We discuss some of these features, which are still crucial to current-generation Datto SIRIS models, in greater depth below.)

Original SIRIS 1

Datto introduced the first SIRIS in January 2011, dubbing it “a departure from the conventional method of data backup that will change the way backup is done forever.”

At the time of its release, Datto was just beginning to get the word out about its Inverse Chain Technology. A press release about the SIRIS 1 explained how the technology prevented file damage—common with conventional backup methods—“because the base [backup] image is always the newest file. Datto’s new technology ensures that the full image is always at the front of the backup chain, and does not rely on past files for recovery.”

Some of the original models included the S250, S500 and S100, with storage capacities of up to 2TB.

Additional SIRIS Features

We’ve barely touched on the numerous features that make the Datto SIRIS the preferred business continuity solution for thousands of organizations around the globe.

Here are some more capabilities built into SIRIS that make it unique:

  • Automatic backup testing: Datto’s Advanced Screenshot Verification checks that a backup is viable by taking automatic screenshots and test-booting protected servers.
  • Ransomware protection: All SIRIS devices now feature built-in ransomware detection, alerting admins to the very first signs of infection, so that backups can be restored with little to no disruption.
  • Hybrid virtualization: Available on all SIRIS devices, hybrid virtualization improves fault tolerance and reduces reliance on bandwidth by allowing you to boot a virtualized node in Datto’s cloud and then manage it with local hardware.
  • Greater insight into data changes: In addition to full-scale recoveries, Datto’s Backup Insights platform makes it easy to restore individual files and folders. Even without access to file names or dates, you can quickly identify which files have been deleted, modified or created between two backups.

Frequently Asked Questions (FAQs) about the Datto SIRIS Models

1. How does the Datto SIRIS work?

The Datto SIRIS is a business continuity solution that backs up data locally and replicates it to the Datto Cloud. It creates image-based backups that can be booted as virtual machines for instant access to protected data and applications. Unlike traditional incremental backups, SIRIS stores each recovery point in a fully constructed state.

2. What is the difference between the Datto SIRIS and Datto ALTO?

The main difference between the Datto SIRIS and ALTO is that ALTO is designed for smaller businesses. The functionality of both devices is largely the same, but ALTO has a maximum storage capacity of 1TB while the high-end SIRIS models can store up to 60TB.

Another difference is that ALTO’s Instant Virtualization is available exclusively via the Datto Cloud, whereas SIRIS allows virtualization on-site or off-site.

3. What is the difference between Virtual SIRIS and SIRIS Imaged?

The difference between Virtual SIRIS and SIRIS Imaged is that Virtual SIRIS is deployed as a virtual machine. Both are software-only deployments that use your existing hardware and offer the full functionality of the Datto SIRIS. But Virtual SIRIS runs on a virtual machine via VMware or Hyper V.

4. Why Datto BCDR?

Datto delivers the most comprehensive suite of  products and services to help protect valuable business data. In addition to the Datto SIRIS, Datto offers the Datto ALTO for small business protection as well as the Datto NAS for smarter file backup, Datto SaaS Protection for M365 and Google Workspace (formally Backupify), Datto Continuity for MS Azure, and Datto Cloud Continuity for PCs.

Get More Information

Get to know the Datto SIRIS by requesting a free demo from Invenio IT. Our business continuity experts are happy to go over your options and answer any questions you have. Contact us today at (646) 395-1170 or

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