Mitigating VM creation failures during Azure restores

Topic

This article discusses troubleshooting for VM creation errors during Microsoft Azure restores

Environment

  • Datto Backup for Microsoft Azure

Description

Several errors can occur when the Datto Backup for Microsoft Azure creates VMs after uploading disks to Azure, including:

  • more disks created than the target VM can hold
  • conflicting VM names
  • mid-upload public IP address deletion

Troubleshooting steps

Determine the error

Position your cursor over the restore failure. this will show the error message. Common error message types include:

  • Messages stating the CPU quota being exceeded. For example: Creating the resource of type <resource-type> would exceed the quota of <number> resources of type <resource-type> per resource group. The current resource count is <number>, please delete some resources of this type before creating a new one.
  • Messages stating the subnet targeted by the restore does not have enough addressing capacity. For example: Subnet <subnet> with address prefix <cidr> does not have enough capacity for 1 IP addresses.
  • Other issues that would cause a VM not to deploy.

If you do not see an error message, contact Datto Technical Support.

Spinning up the VM

Use the following steps to spin up a troubleshooting VM.

  1. Find the OS disk. this will have been restored to whichever resource group the partner specified.

  2. Click the disk, then click Create VM.

  3. Select the appropriate inputs from the VM. Input options include resource group, VM name, VM size, networking rules, etc.

    During this step, it is important to recall which error message you saw when you checked the failed VM. If you're out of (e.g.) B series VM quota, then you'll need to ensure that you've either increased the quota, or that you select a VM family which has quota. The Azure UI should give good hints if you're exceeding quotas or deploying to a subnet with no IP space.

  4. If the VM originally had data disks, click Next Disks, find the Data Disks section, and click Attach an existing disk. Repeat this step until all restored data disks are attached.

  5. Complete the VM creation process as you would for any other VM in your environment (e.g. selecting things like boot diagnostics, tags, public IP addresses).