How to Find and Eliminate Idle Azure Resources

Idle resources are the low-hanging fruit of cloud cost optimization. They're resources that exist in your Azure subscription, incur charges, but provide no value — nobody is using them, and they're often forgotten.

The most common idle resources

1. Stopped (but not deallocated) VMs

This is the #1 money waster in Azure. When you "stop" a VM from the operating system, Azure keeps the compute allocated and continues billing at full price. You need to deallocate the VM from the Azure portal or CLI to actually stop billing.

CostBeacon's StoppedNotDeallocatedVmRule catches this automatically by checking the power state metadata of every VM in your subscriptions.

2. Unattached managed disks

When you delete a VM, Azure doesn't automatically delete its disks. These orphaned disks sit in your subscription billing $5-$150/mo depending on size and tier. Over time, they accumulate.

3. Unused public IPs

Public IP addresses cost ~$3.65/mo when not attached to any resource. After decommissioning a VM or load balancer, the public IP often gets left behind.

4. Stale disk snapshots

Snapshots are great for backups and migrations, but they're often created "just in case" and never cleaned up. A snapshot of a 256GB disk costs the same as storing 256GB — every month.

5. Idle NAT Gateways and Firewalls

NAT Gateways cost ~$32/mo and Azure Firewalls cost ~$1,277/mo — even with zero traffic. These are often provisioned during initial setup and forgotten after workloads move.

How to find them

Azure Advisor catches some of these, but its coverage is limited. It won't flag stopped-but-allocated VMs, stale snapshots, orphaned NICs, or idle firewalls.

CostBeacon runs 42 purpose-built rules that check for all of these patterns automatically. Connect your Azure subscription and run a scan — you'll see every idle resource with estimated monthly savings.

What to do about them

For each idle resource, the decision is simple:

• Delete it if nobody needs it (take a snapshot first for safety)
• Deallocate it if you need to keep it but don't need it running
• Downsize it if it's needed but over-provisioned

The average Azure subscription has 10-15% waste from idle resources alone. For a $50k/mo Azure bill, that's $5,000-$7,500/mo in savings — just from cleaning up what's not being used.