VM states (running, stopped, deallocated) in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

Understanding VM State Impact on Billing

You have an Azure VM that you stopped from the Azure portal. What is the billing state of this VM?

A You are billed only for storage but not compute because the VM is deallocated.

B You are not billed at all because the VM is stopped and deallocated automatically.

C You are still billed for the VM's compute resources because the VM is only stopped but not deallocated.

D You are billed for both compute and storage because the VM is running.

💡 Hint

Stopping a VM from the portal does not always release compute resources.

Stopping a VM from the Azure portal stops the OS but does not deallocate the VM. Compute resources are still reserved and billed. To stop billing compute, the VM must be deallocated.

🧠 Conceptual

intermediate

Difference Between Stopped and Deallocated States

Which statement correctly describes the difference between the 'Stopped' and 'Deallocated' states of an Azure VM?

A 'Stopped' means the VM is deleted; 'Deallocated' means the VM is paused.

B 'Stopped' means the VM is powered off but compute resources are still reserved; 'Deallocated' means compute resources are released.

C 'Stopped' means the VM is running but idle; 'Deallocated' means the VM is running with no network.

D 'Stopped' and 'Deallocated' are the same state with different names.

💡 Hint

Think about resource reservation and billing implications.

'Stopped' means the VM is powered off but compute resources remain allocated and billed. 'Deallocated' means the VM is fully shut down and compute resources are released, stopping billing for compute.

❓ Configuration

advanced

Automating VM Deallocation via Azure CLI

You want to write an Azure CLI command to stop and deallocate a VM named 'webserver1' in resource group 'prod-rg'. Which command correctly achieves this?

A az vm deallocate --resource-group prod-rg --name webserver1

B az vm shutdown --resource-group prod-rg --name webserver1

C az vm stop --resource-group prod-rg --name webserver1

D az vm power-off --resource-group prod-rg --name webserver1

💡 Hint

Stopping a VM does not deallocate it. Which command explicitly deallocates?

'az vm deallocate' stops the VM and releases compute resources, putting it in the deallocated state. 'az vm stop' only stops the VM but keeps compute allocated.

❓ Architecture

advanced

Designing Cost-Efficient VM Usage

You have a development VM that is used only during business hours (9am-5pm). To minimize costs, which VM state management strategy is best?

A Delete the VM at 5pm and recreate it at 9am to save costs.

B Stop the VM at 5pm and start it at 9am to avoid compute charges during off-hours.

C Leave the VM running but shut down the OS at 5pm to save costs.

D Deallocate the VM at 5pm and start it at 9am to avoid compute charges during off-hours.

💡 Hint

Consider which state stops billing for compute resources.

Deallocating the VM releases compute resources and stops billing for compute. Stopping the VM without deallocation still incurs compute charges. Deleting and recreating is inefficient and slow.

❓ security

expert

Security Implications of VM States

Which VM state provides the highest security assurance that the VM is not accessible over the network and cannot be accidentally started?

A Stopped (deallocated)

B Stopped (allocated)

C Paused

D Running

💡 Hint

Think about network accessibility and resource allocation.

A VM in the 'Stopped (deallocated)' state has its compute resources released, is not running, and is not accessible over the network. This state prevents accidental start and network exposure. 'Stopped (allocated)' VMs may still have network interfaces active.

Practice

1. What does the deallocated state mean for an Azure VM?

easy

A. The VM is off and resources are freed.

B. The VM is running and using resources.

C. The VM is off but still reserving resources.

D. The VM is paused but still running.

Solution

1. Step 1: Understand VM states

   Azure VMs can be running, stopped, or deallocated. Running means active, stopped means off but resources reserved, deallocated means off and resources freed.

2. Step 2: Identify deallocated meaning

   Deallocated means the VM is turned off and Azure releases the compute resources, so you don't pay for them.

3. Final Answer:

   The VM is off and resources are freed. -> Option A

4. Quick Check:

   Deallocated = off + freed resources [OK]

Hint: Deallocated means VM off and no resources reserved [OK]

Common Mistakes:

• Confusing stopped with deallocated
• Thinking deallocated still uses resources
• Assuming deallocated means paused

2. Which Azure CLI command correctly stops a VM and releases its resources?

easy

A. az vm pause --name MyVM --resource-group MyGroup

B. az vm stop --name MyVM --resource-group MyGroup

C. az vm shutdown --name MyVM --resource-group MyGroup

D. az vm deallocate --name MyVM --resource-group MyGroup

Solution

1. Step 1: Review Azure CLI commands for VM states

   To stop a VM but keep resources, use az vm stop. To stop and free resources, use az vm deallocate.

2. Step 2: Identify command that releases resources

   az vm deallocate stops the VM and releases compute resources, matching the question.

3. Final Answer:

   az vm deallocate --name MyVM --resource-group MyGroup -> Option D

4. Quick Check:

   Deallocate command frees resources [OK]

Hint: Use 'deallocate' to stop VM and free resources [OK]

Common Mistakes:

• Using 'stop' which keeps resources reserved
• Confusing 'shutdown' with deallocate
• Using non-existent 'pause' command

3. If an Azure VM is in the stopped state, what happens to billing for compute resources?

medium

A. Billing doubles due to stopped state overhead.

B. Billing stops immediately as VM is off.

C. Billing continues because resources are reserved.

D. Billing pauses but storage costs continue.

Solution

1. Step 1: Understand billing for stopped VMs

   When a VM is stopped (not deallocated), compute resources are still reserved, so billing continues for compute.

2. Step 2: Differentiate from deallocated state

   Only when VM is deallocated are compute resources freed and billing stops for compute.

3. Final Answer:

   Billing continues because resources are reserved. -> Option C

4. Quick Check:

   Stopped = billing continues [OK]

Hint: Stopped VMs still reserve resources and incur charges [OK]

Common Mistakes:

• Assuming billing stops when VM is stopped
• Confusing storage billing with compute billing
• Thinking stopped means deallocated

4. You tried to start a VM but got an error because it is in the deallocated state. What should you do to fix this?

medium

A. Run az vm start to allocate and start the VM.

B. Run az vm stop to release resources first.

C. Run az vm restart to reset the VM state.

D. Run az vm deallocate again to confirm.

Solution

1. Step 1: Understand VM start from deallocated

   A VM in deallocated state has no resources allocated. To use it, you must start it which allocates resources and powers it on.

2. Step 2: Identify correct command to allocate and start

   az vm start allocates resources and powers on the VM, fixing the error.

3. Final Answer:

   Run az vm start to allocate and start the VM. -> Option A

4. Quick Check:

   Start command allocates resources [OK]

Hint: Use 'start' to allocate and power on deallocated VM [OK]

Common Mistakes:

• Trying to stop or deallocate an already deallocated VM
• Using restart which requires VM to be running
• Not allocating resources before starting

5. You want to save costs by stopping your VM but keep its IP address and disk data intact. Which state should you use and why?

hard

A. Use running state but reduce VM size to save costs.

B. Use stopped state because it keeps resources reserved including IP and disks.

C. Use deallocated state because it frees all resources including IP address.

D. Use stopped state because it frees compute resources but keeps IP.

Solution

1. Step 1: Understand resource reservation in stopped state

   When a VM is stopped (not deallocated), compute resources are reserved, so the IP address and disk data remain intact.

2. Step 2: Compare with deallocated state

   Deallocated frees compute resources and may release dynamic IP addresses, so IP might change.

3. Final Answer:

   Use stopped state because it keeps resources reserved including IP and disks. -> Option B

4. Quick Check:

   Stopped = keep IP and disks reserved [OK]

Hint: Stopped keeps IP and disks; deallocated frees resources [OK]

Common Mistakes:

• Choosing deallocated and losing IP address
• Thinking stopped frees compute resources
• Trying to save costs by resizing while running