It’s a question that I get asked quite frequently. Can I vault the backup data from my on-premises Altaro VM Backup server to Microsoft Azure somehow? The answer is yes, however, a lot of people follow this up with the question of whether they can simply use Azure as a storage target or not, which at the time of this writing, the answer is no. Don’t mis-understand, when I say we can’t vault directly to a storage target in Azure, i simply mean our software is not able to vault directly to an Azure storage account. Currently we need software at the receiving end of the vaulting process to receive and process the backup data, that’s where our Altaro Offsite Server software comes into play. Check out Part 2 which describes how to setup an Altaro Offsite Server in Microsoft Azure.

This will be part 1 of a series on hosting offsite backup data in Azure using the Altaro Offsite Server. This post will cover the pricing and planning of the solution, while the next post will actually answer the “howto” question. Let’s get started!

The Altaro Offsite Server

The Altaro Offsite Server software can be installed on any Windows box, and this applies to Azure as well. If you want to store your Altaro offsite copies inside of Azure, step one of the process is to stand up a virtual machine inside of Azure for this use. The system requirements for our offsite server are quite light. We require:

  • Minimum of i5 (or equivalent) processor
  • 75 MB RAM + and additional 75 MB for each concurrent backup/restore

So really….  that’s it! You could provision a fairly light VM to handle this job, or if you’d like to limit additional compute costs from Azure, you could place this function on another server running in Azure (If you have one). Before we cover the howto aspect of this series in the next post, let’s first set some expectations as to the cost of hosting this inside of Azure.

Costs for Hosting an Altaro Offsite Server inside of Microsoft Azure

Before I say anything else regarding this point, please note, that some of the costs discussed below are as I understand them at the time of this writing. Microsoft Azure pricing is changing all the time, and if you’re considering going this route, I highly recommend reviewing the Azure pricing page and the calculator. If you have an Azure rep from Microsoft, I would recommend consulting with them as well. The last thing I want is for you to incur un-expected costs due to confusion of how Azure bills for it’s services. With that said, here are the things you’ll need to worry about paying for….

Compute: When you see this term in regards to Azure pricing, it usually means a virtual machine. You’re paying for compute resources in the form of a VM, and the cost will depend on the sizing of said VM.

Storage:  You’ll have to pay for the storage you use inside of Azure. It’s quite cheap (when you consider the alternatives) and you only pay for what you use. For example, if you’re VHDX is sized at 200GB, but you’re only using 20GB, you only pay for the 20GB number. As for the kind of storage you’ll be paying for, you have two options with our offsite server currently.

1. Page Blobs and Disks

This is the standard storage type for virtual disks attached to a VM inside of Azure. This is likely the most common storage type and is priced at $0.05/GB every month. While this is the most common, there are some limitations. The maximum size of a page blob disk inside of Azure is currently 1TB. If you need anything over and above that you’ll need to add a 2nd disk and setup a storage pool, to make use of both VHDs. Additionally, certain VM sizes inside of azure only allow the attachment of so many block devices. So to get more than 2 or 4, you’ll need to increase the size of your VM instance, which will raise the compute cost, so plan accordingly.

2. Azure Files

Azure Files is a fairly new technology in the Azure solution stack. It essentially allows you to create an SMB share within the Azure file system and present that share to resources. This can be used as a viable storage location for your offsite backups. Azure files is slightly more expensive at $0.08/GB monthly, but it has a 5TB limitation, instead of the 1TB limitation. However, while the Page Blob Disks, can be stripped together to form a storage pool, the same cannot be said of Azure File Shares, so keep that in mind if you anticipate going over 5TB of offsite data.

*A note on storage resiliency in Azure:

For the vast majority of customers using Azure as an offsite backup location, the capabilities of the locally redundant storage account type should suit your needs. A locally redundant storage account will insure that 3 copies of every block of data exist somewhere in that Azure datacenter region. If your organization has more strict requirements, you can opt for the geo-redundant storage, which will provide 6 total copies of each block of data. 3 copies in the main datacenter region, and the other 3 copies located in another datacenter region.

Network Bandwidth: Azure network costs are something that confuse a lot of people, but despite all the complicated descriptions and what not, it boils down to pretty much one statement in the terms of this discussion. Bandwidth is FREE moving data IN to Azure. Egress (outbound) traffic, there is a per/Gb charge. In short, you only pay for bandwidth fees if you actually need to pull data out of the offsite server. The cost at the time of this writing is $0.09/GB per month, over 5GB in the US and Europe. Other regions are slightly more expensive. See the Azure calculator for more detail.

(Optional) Azure VPN Gateway: Depending on your organization’s policies and requirements, you may not be able to vault data over the public web, regardless of whether that data is encrypted or not. (Altaro VM Backup encrypts the data in transit). In this case you’ll have to stand up an additional service inside of Azure to facilitate a site to site VPN between your Azure resources and your on-premises location. This has varying costs depending on the speed required and the number of needed concurrent connections to the VPN.  The below table shows the differences and was pulled from the Azure documentation site at the time of this writing.

AzureVPNDepending on your needs, your VPN costs could be anywhere from $27 to $365 per month. So some research will need to be done if the VPN gateway is something that you will require, and if so, which type.

Additionally, a supported on-premises server or networking device that works with Azure VPN gateways will need to be available. A list of supported devices can be found HERE.


Once you’ve got all this planning out of the way, your comfortable with the pricing and the various components, you’re now ready to start proceeding with the installation of Altaro VM Backup inside of your Azure virtual machine. We’ll be covering that in the next part of this series, so be sure to stay tuned to our blog for that howto.

In the mean time, if you have any questions or concerns with pricing or planning this solution, be sure to let us know if the comments section below!

As always, thanks for reading!