# Ubuntu Installation: Disk Selection Guide

## Problem
Ubuntu installer is trying to use more disk space than the VM's allocated disk, or showing multiple storage devices.

## Solution: Select Only the Correct Disk

During Ubuntu installation, you need to **manually select only the VM's hard disk** and ignore the CD-ROM/ISO.

### Step-by-Step: Disk Selection

1. **During Ubuntu Installation:**
   - When you reach **"Storage configuration"** or **"Installation type"**
   - Select **"Custom storage layout"** or **"Manual"**

2. **Identify the Correct Disk:**
   - Look for disk with size matching your VM:
     - **VM 100 (cloudflare-tunnel)**: ~40GB disk
     - **VM 101 (k3s-master)**: ~80GB disk
     - **VM 102 (git-server)**: ~100GB disk
     - **VM 103 (observability)**: ~200GB disk
   - **Ignore the CD-ROM/ISO** (usually shows as ~3GB or "CD/DVD")

3. **Select Only the Hard Disk:**
   - Click on the **hard disk** (not the CD-ROM)
   - The disk should show as:
     - **Device**: `/dev/sda` or `/dev/vda` (SCSI/VirtIO)
     - **Size**: Matches your VM's disk size
     - **Type**: "SCSI disk" or "VirtIO Block Device"

4. **Partition the Disk:**
   - Select the hard disk
   - Click **"Add partition"** or **"Use entire disk"**
   - Recommended: **"Use entire disk"** for simplicity
   - Or create partitions:
     - **EFI Boot**: 512MB (if UEFI)
     - **Root (/)**: Rest of disk
     - **Swap**: Optional (2-4GB)

5. **Continue Installation:**
   - Review the partition layout
   - Ensure only the hard disk is selected
   - Click **"Done"** or **"Continue"**

### What to Ignore

- ❌ **CD/DVD drive** (ide2) - This is the Ubuntu ISO, NOT a disk
- ❌ **Any device showing ~3GB** - This is likely the ISO
- ❌ **Floppy drive** (if shown) - Ignore this

### Expected Disk Sizes

| VM | Disk Size | Device Name |
|----|-----------|-------------|
| VM 100 | 40GB | `/dev/sda` or `/dev/vda` |
| VM 101 | 80GB | `/dev/sda` or `/dev/vda` |
| VM 102 | 100GB | `/dev/sda` or `/dev/vda` |
| VM 103 | 200GB | `/dev/sda` or `/dev/vda` |

### Troubleshooting

**Installer shows "Not enough space":**
- You might have selected the CD-ROM instead of the hard disk
- Go back and select the larger disk (matches your VM size)

**Multiple disks shown:**
- Select only the disk matching your VM's size
- Ignore the CD-ROM (smaller, ~3GB)

**Can't find the correct disk:**
- Look for the largest disk (matches your VM size)
- Check device names: `/dev/sda` or `/dev/vda` for SCSI/VirtIO

### Quick Reference

**During Installation:**
1. **Storage Configuration** → **Custom/Manual**
2. **Select disk** matching your VM size (40GB, 80GB, 100GB, or 200GB)
3. **Ignore CD-ROM** (smaller, ~3GB)
4. **Use entire disk** or create partitions
5. **Continue** installation

### Visual Guide

```
Ubuntu Installer Storage Selection:

┌─────────────────────────────────────┐
│ Storage Devices                     │
├─────────────────────────────────────┤
│ ☐ CD/DVD Drive (ide2)               │  ← IGNORE THIS
│   3.2 GB - ubuntu-24.04.iso         │
├─────────────────────────────────────┤
│ ☑ SCSI Disk (scsi0)                 │  ← SELECT THIS
│   40 GB - local-lvm:vm-100-disk-0   │
└─────────────────────────────────────┘
```

## Summary

- ✅ **Select only the hard disk** (matches your VM size)
- ❌ **Ignore the CD-ROM** (ISO image, ~3GB)
- ✅ **Use entire disk** for simplicity
- ✅ **Continue** with installation