Instance states (running, stopped, terminated) in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when you stop a Google Compute Engine instance?

You have a Google Compute Engine virtual machine instance currently in the running state. You issue a stop command on this instance. What is the resulting state and behavior of the instance?

A The instance state changes to <em>stopped</em>, the VM is shut down, and you stop incurring charges for the VM's CPU and memory, but persistent disk charges continue.

B The instance state changes to <em>terminated</em>, the VM is deleted permanently and all data on the persistent disk is lost.

C The instance state remains <em>running</em>, but the VM is paused and you continue to be charged for CPU and memory.

D The instance state changes to <em>stopped</em>, but the VM continues running in the background and you continue to be charged for CPU and memory.

💡 Hint

Think about what happens to billing and data when you stop a VM but do not delete it.

Stopping a VM shuts it down and changes its state to stopped. You stop paying for CPU and memory, but persistent disk charges continue because the disk still exists. The VM is not deleted.

🧠 Conceptual

intermediate

Which instance state indicates a VM has been permanently deleted?

In Google Cloud Platform, which instance state means the virtual machine no longer exists and cannot be restarted?

A Terminated

B Stopped

C Running

D Paused

💡 Hint

Consider which state means the VM is gone for good.

The terminated state means the VM has been deleted permanently and cannot be restarted. Running means active, stopped means shut down but still exists, paused is not a standard GCP state.

❓ Architecture

advanced

Designing a cost-efficient VM lifecycle using instance states

You want to design a system where your VM instances are only charged for CPU and memory during business hours (9am-5pm), but data must persist 24/7. Which instance state transitions should your automation perform daily?

A Create new instances at 9am, delete instances at 5pm.

B Start instances at 9am (state: running), stop instances at 5pm (state: stopped).

C Pause instances at 5pm, resume instances at 9am.

D Terminate instances at 5pm, recreate instances at 9am.

💡 Hint

Think about which states preserve data and reduce charges.

Starting instances at 9am and stopping at 5pm keeps data on persistent disks and stops CPU/memory charges outside business hours. Deleting or terminating would lose data or incur recreation overhead.

❓ security

advanced

Security implications of instance states in GCP

Which instance state poses the highest security risk if an attacker gains access to your Google Cloud project, assuming no additional protections?

A Stopped - attacker can start the VM and access data on disk.

B Terminated - attacker cannot access the VM or data because it is deleted.

C Running - attacker can access the live VM and data in memory.

D Paused - attacker can resume the VM and access data.

💡 Hint

Consider which state allows immediate access to running processes and memory.

A running VM is active and accessible, so an attacker can interact with the live system and data in memory. Stopped or terminated states require additional steps to access data.

✅ Best Practice

expert

Choosing the correct instance state for disaster recovery readiness

Your company requires that VM instances be quickly recoverable after a disaster, with minimal data loss and cost efficiency. Which instance state strategy best meets this requirement?

A Keep instances in <em>running</em> state 24/7 to ensure immediate availability.

B Pause instances during off-hours and resume during business hours.

C Terminate instances daily and recreate from backups when needed.

D Keep instances <em>stopped</em> with persistent disks and snapshots taken regularly for fast restart.

💡 Hint

Balance cost, recovery speed, and data safety.

Stopping instances preserves data on disks and allows quick restart. Regular snapshots add data protection. Running 24/7 is costly, terminating loses data, pausing is not a standard GCP state.

Practice

1. What does the RUNNING state of a Google Cloud VM instance indicate?

easy

A. The VM is paused and cannot be restarted

B. The VM is permanently deleted

C. The VM is active and ready to use

D. The VM is being created

Solution

1. Step 1: Understand VM states

   The RUNNING state means the virtual machine is powered on and operational.

2. Step 2: Compare with other states

   TERMINATED means stopped but restartable; DELETED means removed permanently.

3. Final Answer:

   The VM is active and ready to use -> Option C

4. Quick Check:

   RUNNING = active and ready [OK]

Hint: RUNNING means VM is active and ready [OK]

Common Mistakes:

• Confusing TERMINATED with RUNNING
• Thinking DELETED means stopped
• Assuming RUNNING means VM is paused

2. Which command correctly stops a running Google Cloud VM instance named my-vm using gcloud CLI?

easy

A. gcloud compute instances stop my-vm

B. gcloud compute instances delete my-vm

C. gcloud compute instances terminate my-vm

D. gcloud compute instances suspend my-vm

Solution

1. Step 1: Identify the correct stop command

   The command to stop a VM is gcloud compute instances stop.

2. Step 2: Check other commands

   delete removes the VM, terminate is not a valid gcloud command, suspend preserves memory state but is different from stop.

3. Final Answer:

   gcloud compute instances stop my-vm -> Option A

4. Quick Check:

   Stop VM = gcloud compute instances stop [OK]

Hint: Use 'stop' to halt VM without deleting [OK]

Common Mistakes:

• Using delete instead of stop
• Typing terminate which is invalid
• Confusing suspend with stop

3. Given this gcloud command output:

NAME    ZONE       STATUS
vm-1    us-central1-a  TERMINATED
vm-2    us-central1-a  RUNNING
vm-3    us-central1-a  TERMINATED

Which VM(s) can be restarted without creating a new instance?

medium

A. Only vm-2

B. vm-1 and vm-3

C. All vm-1, vm-2, and vm-3

D. None of them

Solution

1. Step 1: Understand TERMINATED state

   TERMINATED means the VM is stopped but can be restarted later.

2. Step 2: Identify which VMs are TERMINATED

   vm-1 and vm-3 are TERMINATED, so they can be restarted; vm-2 is already RUNNING.

3. Final Answer:

   vm-1 and vm-3 -> Option B

4. Quick Check:

   TERMINATED = restartable VMs [OK]

Hint: TERMINATED means stopped but restartable [OK]

Common Mistakes:

• Thinking RUNNING VMs need restart
• Assuming TERMINATED means deleted
• Selecting all VMs regardless of state

4. You tried to restart a VM but got an error saying the instance does not exist. What is the most likely cause?

medium

A. The VM was DELETED and no longer exists

B. The VM is in SUSPENDED state

C. The VM is in TERMINATED state

D. The VM is in RUNNING state

Solution

1. Step 1: Analyze error message

   Error 'instance does not exist' means the VM resource is gone.

2. Step 2: Match with VM states

   Only DELETED means the VM is removed permanently; RUNNING, TERMINATED, SUSPENDED still exist.

3. Final Answer:

   The VM was DELETED and no longer exists -> Option A

4. Quick Check:

   Deleted VM = does not exist error [OK]

Hint: Deleted VM no longer exists, causing errors [OK]

Common Mistakes:

• Confusing TERMINATED with DELETED
• Assuming STOPPED means deleted
• Ignoring error message meaning

5. You want to save costs by stopping a VM but keep its data and configuration intact for later use. Which state should you put the VM in, and why?

hard

A. RUNNING, because it keeps the VM active and ready

B. SUSPENDED, because it pauses the VM without data loss

C. DELETED, because it frees all resources immediately

D. TERMINATED, because it stops the VM but preserves data and allows restart

Solution

1. Step 1: Understand cost-saving states

   Stopping a VM saves costs but keeps data if the VM is TERMINATED.

2. Step 2: Evaluate options

   RUNNING uses full resources; DELETED removes VM and data; SUSPENDED preserves memory but standard stop uses TERMINATED.

3. Final Answer:

   TERMINATED, because it stops the VM but preserves data and allows restart -> Option D

4. Quick Check:

   Stop VM = TERMINATED state for cost saving [OK]

Hint: TERMINATED stops VM but keeps data for restart [OK]

Common Mistakes:

• Choosing RUNNING to save costs
• Deleting VM to save costs but losing data
• Choosing SUSPENDED instead of TERMINATED