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Rightsizing · Low severity

Azure Stateless VM Could Use Ephemeral OS Disk

An ephemeral OS disk lives on the VM's own local storage instead of remote Azure Storage, so a stateless VM on a managed OS disk is paying to persist an OS state it never keeps.

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Azureprovider
Lowseverity
Savingswhere it shows up
Manualfix, steps written out

Azure

Found, explained, handed over.

Findings with a dollar figure attached, idle, oversized, orphaned, unscheduled and undiscounted spend.

01

Detect

ZopNight checks this automatically across Azure, with read-only access to the account.

02

Explain

Every finding says exactly what to change: Move the stateless VM to an ephemeral OS disk. Where the saving can be proven it is priced; where it cannot, the finding says so.

03

Fix

The finding opens with the fix already written out, step by step, so it is one ticket, not an investigation.

Applies to
Virtual Machines on Azure
The fix, by hand
  1. Verify the workload is truly stateless: no app data on the OS disk, /etc is provisioned via cloud-init or images.
  2. Verify the VM SKU supports ephemeral OS disks (check size's Cache size / Temp storage column in the SKU table).
  3. Recreate the VM from the same image with ephemeral OS disk enabled (set diffDiskSettings.option=Local in ARM / CLI).
  4. Reattach data disks and reconfigure networking on the new VM.
  5. Delete the old VM and its managed OS disk.

These are the steps the finding carries in the product.

Category
Rightsizing. Resources sized for headroom they never use. A smaller size runs the same workload for less.
Where it appears
The Savings tab of Recommendations, with every affected resource listed.
Rule ID
RC-1309
Full reference

Azure Stateless VM Could Use Ephemeral OS Disk

Related checks

Azure VM Antimalware Not EnabledAzureAzure VM Backup Not EnabledAzureAzure VM Disk Encryption Not EnabledAzureAzure VM JIT Access Not EnabledAzureAzure VM Missing Deletion ProtectionAzureAzure VM Update Management Not EnabledAzure

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Multi-cloud automation· Production-ready in 30 min· SOC 2 · ISO 27001· 20–60% off the bill, first month· 4 platforms · 1 console· Multi-cloud automation· Production-ready in 30 min· SOC 2 · ISO 27001· 20–60% off the bill, first month· 4 platforms · 1 console·