Docker Volumes: Persistência e Performance 💾

╔═══════════════════════════════════════╗
║           VOLUME ANATOMY              ║
║                                       ║
║    [Container] ←→ [Volume] ←→ [Host]  ║
║         ↑          ↑         ↑        ║
║    [Bind Mount] [tmpfs] [Block Device]║
║                                       ║
╚═══════════════════════════════════════╝

Volume Types 📦

Named Volumes

# Criar volume nomeado
docker volume create data-volume

# Usar volume
docker run -v data-volume:/app/data nginx

# Inspecionar volume
docker volume inspect data-volume

Bind Mounts

# Montar diretório do host
docker run -v /host/path:/container/path nginx

# Modo somente leitura
docker run -v /host/config:/app/config:ro nginx

tmpfs Mounts

# Montar volume em memória
docker run --tmpfs /app/cache nginx

# Configurar tamanho
docker run --tmpfs /app/cache:size=100M nginx

Volume Management 🛠️

Basic Operations

# Listar volumes
docker volume ls

# Remover volume
docker volume rm volume_name

# Remover volumes não utilizados
docker volume prune

# Backup de volume
docker run --rm \
  -v volume_name:/source \
  -v $(pwd):/backup \
  alpine tar -czf /backup/volume.tar.gz -C /source .

Volume Drivers

# Criar volume com driver específico
docker volume create \
  --driver local \
  --opt type=btrfs \
  --opt device=/dev/sda1 \
  btrfs-volume

# Volume NFS
docker volume create \
  --driver local \
  --opt type=nfs \
  --opt o=addr=192.168.1.1,rw \
  --opt device=:/path/to/dir \
  nfs-volume

Performance Optimization 🚀

Cache Configuration

# Volume para cache
docker volume create \
  --driver local \
  --opt type=tmpfs \
  --opt device=tmpfs \
  --opt o=size=1g \
  cache-volume

# Usar cache
docker run \
  -v cache-volume:/app/cache \
  --memory-swappiness=0 \
  app

I/O Tuning

version: '3.8'
services:
  db:
    volumes:
      - data:/var/lib/mysql
    deploy:
      resources:
        limits:
          blkio-weight: 1000

volumes:
  data:
    driver_opts:
      type: 'none'
      o: 'bind'
      device: '/mnt/high-perf-disk'

Docker Compose Integration 📋

Volume Configuration

version: '3.8'
services:
  web:
    volumes:
      - web-data:/var/www/html
      - ./config:/etc/nginx:ro
      - type: tmpfs
        target: /tmp
        tmpfs:
          size: 100M

volumes:
  web-data:
    driver: local
    driver_opts:
      type: 'none'
      o: 'bind'
      device: '/data/web'

Backup Strategy

services:
  backup:
    image: alpine
    volumes:
      - data-volume:/source:ro
      - ./backups:/backup
    command: tar -czf /backup/backup.tar.gz -C /source .
    deploy:
      restart_policy:
        condition: none

Volume Security 🔒

Permission Management

# Definir permissões
docker run \
  -v data:/app/data \
  --user 1000:1000 \
  app

# SELinux context
docker run \
  -v data:/app/data:z \
  app

Access Control

services:
  app:
    volumes:
      - type: volume
        source: sensitive-data
        target: /app/data
        read_only: true
        volume:
          nocopy: true

Troubleshooting 🔍

Common Issues

# Verificar montagens
docker inspect -f '{{ .Mounts }}' container_id

# Checar permissões
docker run --rm -v problem-volume:/vol alpine ls -la /vol

# Verificar espaço
docker system df -v

Debug Tools

# Inspecionar volume
docker volume inspect volume_name

# Testar acesso
docker run --rm \
  -v volume_name:/test \
  busybox touch /test/testfile

# Verificar logs
docker logs container_id 2>&1 | grep volume

Best Practices 💡

Volume Design

Use named volumes para dados persistentes
Bind mounts para desenvolvimento
tmpfs para dados sensíveis temporários
Planeje backup e restore
Monitore uso de espaço

Performance Tips

Use volumes locais para I/O intensivo
Configure cache apropriadamente
Evite bind mounts em produção
Monitore performance de I/O
Use volumes dedicados para dados críticos

Learn Docker Help

Docker Volumes: Persistência e Performance 💾

Volume Types 📦

Named Volumes

Bind Mounts

tmpfs Mounts

Volume Management 🛠️

Basic Operations

Volume Drivers

Performance Optimization 🚀

Cache Configuration

I/O Tuning

Docker Compose Integration 📋

Volume Configuration

Backup Strategy

Volume Security 🔒

Permission Management

Access Control

Troubleshooting 🔍

Common Issues

Debug Tools

Best Practices 💡

Volume Design

Performance Tips

Waifu Volume Tips 🎀

Próximos Passos 🎯

Referências 📚