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100 Days of Cloud (Azure)Engineering Note

Attaching A Managed Data Disk to VM

Attach a Managed Data Disk to an Azure Virtual Machine and configure it for use.

🎯 Objective

Attach a Managed Data Disk to an Azure Virtual Machine and configure it for use.

🤔 What is a Managed Data Disk?

A Managed Disk in Microsoft Azure is a separate storage volume attached to a VM.

👉 Types of disks:

OS Disk → Contains operating system
Data Disk → Used for:
Application data
Databases
Logs

🧱 Architecture Overview

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🔗 Method 1: Attach Disk via Azure Portal

🪜 Steps:

1. Go to Azure Portal

1. Navigate to Virtual Machines

1. Select your VM

1. Click Disks

1. Click + Create and attach a new disk

⚙️ Configure Disk:

Name: myDataDisk
Size: e.g. 10 GiB
Type:
Standard HDD
Standard SSD
Premium SSD

1. Click Save

💻 Method 2: Attach Disk via Azure CLI

🔹 Step 1: Create a Managed Disk

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az disk create \
--resource-group myResourceGroup \
--name myDataDisk \
--size-gb10

🔹 Step 2: Attach Disk to VM

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az vm disk attach \
--resource-group myResourceGroup \
--vm-name myVM \
--name myDataDisk

🧪 Step 3: Configure Disk Inside VM (Linux)

After attaching, SSH into your VM:

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ssh user@your-vm-ip

🔍 1. Check New Disk

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lsblk

👉 You will see something like:

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sda    30G  (OS disk)
sdb    10G  (New data disk)

🧱 2. Create Partition

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sudo fdisk /dev/sdb

Inside fdisk:

Press n → new partition
Press w → write changes

🧾 3. Format Disk

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sudo mkfs.ext4 /dev/sdb1

📂 4. Create Mount Point

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sudomkdir /data

🔗 5. Mount Disk

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sudo mount /dev/sdb1 /data

🔄 6. Make Mount Persistent

Edit /etc/fstab:

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sudo nano /etc/fstab

Add:

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/dev/sdb1 /data ext4 defaults,nofail02

🧪 Verify Mount

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df-h

⚠️ Important Notes

Data disk is independent of OS disk
You can:
Detach
Resize
Snapshot

👉 Data persists even if VM is deleted (if configured)

🧠 Real-World Use Case

🗄️ Store database files on data disk
📦 Separate logs from OS
🚀 Improve performance using Premium SSD

📌 Summary