Azure Managed Disks and Scale Sets come to general availability

Another day, another nifty Microsoft release. This one’s for general availability of Azure Managed Disks and larger Scale Sets. Built with the needs of both IaaS and PaaS users in mind, having Azure Managed Disks in general availability means that you get PaaS-like support of automated disk management without worrying about the nuances or complexity of managing your storage solution.

As Microsoft calls it, this is the “full power and control you expect and love with Azure VMs — a ‘PaaS bridge’ on our IaaS VMs” with “the agility of PaaS to the comfort of IaaS.”

Azure Virtual Machine Scale Sets

With this release to GA also comes the release of Azure VM Scale Sets (VMSS) which help reliably deploy cloud infrastructure without massive overhead of coordinating multiple resources. VMSS lets you deploy and manage sets of identical VMs that are all configured the same. This ensures what Microsoft calls “autoscale” without pre-provisioning each server one at a time. I still remember the days when I was following a checklist of configurations but clearly we’re seeing massive virtualization progress on that front everywhere as the technologies continue to improve and support large scale deployments. With VMSS, you can build large scale infrastructures that can operate across the enterprise, be it big data, big compute, or containerized workloads.

VMSS simplifies application management as well with load balancing and automated application scale. Going a step further, automated disk management allows simpler storage across a larger scale: attaching data disks to every instance which supports a VM scale set of up to 1,000 virtual machines (up from 100).

Azure Managed Disks

Azure Managed Disks are an upgrade from the traditional storage account scale management you may be used to. Managed Disks are a resource of Azure Resource Manager (ARM), can be built off templates, and support Standard (backed by HDDs) and Premium (backed by SSDs) disk types.

With Managed Disks, all you need to do is specify the size and type of disk desired and ARM handles the rest. Disks can be created from scratch (blank disk), from a VHD in a storage account, or from an image as part of the creation of a virtual machine. Existing ARM VMs can also be migrated to a VM with a managed disk easily with a simple reboot and without the necessity to reconfigure your networking or security rules to accommodate the change.

Getting started

To create a Virtual Machine with managed disks, just run the following command on the command line:
$ az vm create -g myResourceGroup -n myLinuxVM –image RHEL –size Standard_DS3_v2 –data-disk-sizes-gb 128

You can also go to the portal and select “Use managed disks” to create a VM in the graphical user interface:

Getting started with Azure Managed Disks

Snapshot and backup

Azure Managed Disks also support snapshot and backup capabilities:

  • Snapshots are just as you know them — the state of the system can be stored within Azure Resource Manager. They exist independent of the source disk and can even be used to create new Managed Disks.
  • Backups allow you to back up your Managed Disks at any point in time. The Azure Backup service can be used to create a backup job with time-based backups, easy restoration of the virtual machine, and backup retention policies.


Managed Disks also can facilitate in creating custom Images via your custom VHD in a storage account or directly from a running virtual machine. Doing this will capture a single image of all Managed Disks associated with a running virtual machine, inclusive of the OS and data disks. Images can also support large VMSS that contain hundreds of VMs without the need to copy or manage storage accounts.

What does this mean for you? Less stress! (Not like the girl below.) There’s less code complexity and simplified management.

Disk management problems

Virtual Machine Scale Set

A single Virtual Machine Scale Set now can accommodate 1,000 VMs which is a 10x scale improvement. With this new increase, you can manage and deploy single clusters, like large-scale Hadoop, DataSynapse, Cassandra, or IIS deployments with ease and with benefits of layer-7 load balancing through Azure Application Gateway.

Want to take advantage of the full 1,000 VMs? Just run this command.

$ az vmss create -g myResourceGroup -n myVMSSName –image ubuntuLTS –instance-count 1000

Other features of note:

  • Application support: These scale sets also support attached disks for improve scalability and support for data-intensive analytics.
  • Security: Granular access control using Azure Role-Based Access Control (RBAC) is supported, which allows you to specify who has read, write, delete, and export permissions. Azure Disk Encryption is also supported so that disks can be fully encrypted.
  • Migration capabilities: Easily move from an existing Azure Resource Manager Virtual Machine to a Managed Disk VM without the need to recreate the VM all while preserving configuration and security of that VM. The VM is available immediately after a reboot. Administrators have full control and can migrate one VM at a time or the entire process can be automated through scripting. Similarly, Managed Disks can be migrated from Standard to Premium without having to delete and reconfigure the VM.

Getting on the bandwagon

So now your interest is piqued — which is exactly what I was going for. General availability means it’s available everywhere. To get started, learn about the various pricing options here.


Photo Credit: Shutterstock, Microsoft

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