🎯 Objective
Resize an Azure Virtual Machine to increase or decrease:
CPU (vCPUs)
Memory (RAM)
Performance tier
🧠What is VM Resizing?
Changing VM size means switching to a different SKU (Virtual Machine size) like:
Standard_B1s → small (low cost)
Standard_D2s_v3 → medium
Standard_E4s_v3 → high memory
👉 Useful for scaling based on workload.
🏗️ Concept
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Azure VM → Resize → New CPU / RAM → Restart VM👉 VM may need to restart during resize.
🛠️ Steps to Change VM Size (Azure Portal)
đź“Ť Step-by-Step:
1. Go to Azure Portal
1. Navigate to Virtual Machines
1. Select your VM
1. In left menu → Click Size
1. Browse available VM sizes
1. Select desired size
1. Click Resize
🔍 What You Will See
Available sizes (filtered by region + availability)
Cost per hour
Specs:
vCPU
RAM
Temp storage
⚠️ Important Notes
🔹 1. VM Must Be Stopped (Sometimes)
If size not available → Stop (deallocate) VM first
👉 From Portal:
Click Stop
Then resize
🔹 2. Region & Hardware Limits
Not all sizes available in all regions
Depends on underlying hardware cluster
🔹 3. Disk Compatibility
Some sizes require Premium Disk support
🔹 4. Temporary Downtime
VM will restart → short downtime
đź’° Cost Impact
👉 Billing changes immediately after resize
🚀 Real Use Cases
Scale up during high traffic
Scale down to save cost
Upgrade performance for database
Testing different VM tiers
🧪 Example Scenario
👉 Your app is slow on:
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Standard_B1s (1 vCPU, 1GB RAM)👉 Upgrade to:
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Standard_D2s_v3 (2 vCPU, 8GB RAM)Result:
Faster response
Better concurrency
🧩 Alternative: Azure CLI
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az vm resize \
--resource-group myResourceGroup \
--name myVM \
--size Standard_D2s_v3🔎 Check Available Sizes via CLI
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az vm list-vm-resize-options \
--resource-group myResourceGroup \
--name myVM \
--output table🧠DevOps Tip
👉 Always monitor before resizing:
CPU usage
Memory usage
👉 Use:
Azure Monitor
Metrics
⚠️ Common Mistakes
❌ Not stopping VM when required
❌ Choosing unsupported size
❌ Ignoring cost increase
❌ Not checking disk compatibility
🔄 Quick Summary
Resize VM from Portal → Size → Select → Resize
May require stop/deallocate
Causes short downtime
Impacts cost & performance