# GRUB Repair Quick Reference

## Essential Commands

### 1. System Detection
```bash
sudo ./grub-repair.sh detect
```

### 2. Complete Boot Repair (Recommended)
```bash
sudo ./grub-repair.sh -d /dev/sda -p 1 -b fix-boot
```

### 3. Check Status
```bash
sudo ./grub-repair.sh status
```

### 4. Clean Up
```bash
sudo ./grub-repair.sh clean
```

## Common Scenarios

### Fresh Boot Repair
```bash
# Detect your system first
sudo ./grub-repair.sh detect

# Then repair (replace /dev/sda with your device)
sudo ./grub-repair.sh -d /dev/sda -p 1 -b fix-boot
```

### GRUB Reinstall Only
```bash
# Mount system
sudo ./grub-repair.sh -d /dev/sda -p 1 mount

# Install GRUB
sudo ./grub-repair.sh install-grub

# Update config
sudo ./grub-repair.sh update-grub

# Unmount
sudo ./grub-repair.sh unmount
```

### EFI Partition Check and Repair
```bash
sudo ./grub-repair.sh -d /dev/sda check-efi
```

## Device Identification

- **Find your disk**: `lsblk` or `fdisk -l`
- **EFI partition**: Usually the first partition (e.g., `/dev/sda1`)
- **Root partition**: Usually the second partition (e.g., `/dev/sda2`)

## Safety Tips

- Always use `-b` flag for backup
- Test on non-critical systems first
- Keep live ISO handy for recovery
- Document your partition layout

## Troubleshooting

- **Permission denied**: Use `sudo`
- **Device not found**: Check with `lsblk`
- **Mount fails**: Use `clean` command first
- **Verbose output**: Add `-v` flag