Azure naming · Microsoft.Compute/disks

disk Managed disk

A managed data disk. CAF uses 'osdisk' for OS disks.

Naming constraints

CAF abbreviationdisk
Resource typeMicrosoft.Compute/disks
Length1–80 characters
CaseMixed case
Allowed charactersAlphanumerics, underscores, and hyphens.
Uniqueness Resource group
SeparatorHyphen
Watch out: OS disks created with a VM get an automatic name (<vm>_OsDisk_1_<guid>) unless you set one. Don't deny non-matching disk names, or VM deployments that rely on the default will fail.

Source: Microsoft Learn, “Naming rules and restrictions for Azure resources”, checked October 2026. Abbreviation from the Cloud Adoption Framework.

Example & copy-ready

A worked name for workload app, env prod, region weu, instance 001.

Example name
disk-app-prod-weu-001 Valid
Validation regex for CI checks or pre-commit hooks (.NET and JavaScript) 
^[A-Za-z0-9_-]{1,80}$
Bicep naming expression 
var name = take('disk-${workload}-${env}-${region}-${instance}', 80)
Terraform local 
locals {
  name = substr(join("-", compact(["disk", var.workload, var.env, var.region, var.instance])), 0, 80)
}

Azure Policy can't evaluate regular expressions, so a policy can check the disk prefix but not the full format. Run the regex in your pipeline, or audit existing names on a schedule.

« Disk encryption set Snapshot »

Uniqueness scope

Unique within the parent resource group. The same name can be reused in a different resource group.

Open in the name generator

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