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备份策略：数据保护最佳实践

📂 devops ⏱ 3 min 558 words

备份策略：数据保护最佳实践

备份策略框架

备份策略核心要素:
  ├── 备份类型: 全量、增量、差异
  ├── 备份频率: 实时、每小时、每天
  ├── 保留策略: 保留周期、版本数量
  ├── 存储位置: 本地、异地、云存储
  └── 验证机制: 定期测试、完整性检查

备份类型

全量备份

#!/bin/bash
# full-backup.sh

BACKUP_DIR="/backup/full/$(date +%Y%m%d)"
mkdir -p $BACKUP_DIR

# 全量备份数据库
pg_dump -U postgres -h localhost -Fc mydb > $BACKUP_DIR/db_full.dump

# 全量备份文件系统
tar -czvf $BACKUP_DIR/files_full.tar.gz \
  /etc/ \
  /home/ \
  /opt/app/config/

# 上传到S3
aws s3 sync $BACKUP_DIR s3://my-backups/full/$(date +%Y%m%d)/

echo "全量备份完成: $BACKUP_DIR"

增量备份

#!/bin/bash
# incremental-backup.sh

BACKUP_DIR="/backup/incremental/$(date +%Y%m%d_%H%M%S)"
mkdir -p $BACKUP_DIR

# 使用tar的增量备份功能
tar -czvf $BACKUP_DIR/files_inc.tar.gz \
  --listed-incremental=/backup/snapshot.snar \
  /home/ \
  /opt/app/

# 数据库WAL归档（PostgreSQL）
# 在postgresql.conf中配置
# archive_mode = on
# archive_command = 'test ! -f /backup/wal/%f && cp %p /backup/wal/%f'

echo "增量备份完成"

差异备份

#!/bin/bash
# differential-backup.sh

FULL_BACKUP_DATE=$(ls -td /backup/full/* | head -1)
DIFF_BACKUP_DIR="/backup/differential/$(date +%Y%m%d)"
mkdir -p $DIFF_BACKUP_DIR

# 差异备份（自上次全量备份以来的变化）
tar -czvf $DIFF_BACKUP_DIR/files_diff.tar.gz \
  --newer=$FULL_BACKUP_DATE \
  /home/ \
  /opt/app/

echo "差异备份完成: $DIFF_BACKUP_DIR"

数据库备份

PostgreSQL备份

#!/bin/bash
# postgres-backup.sh

# 全量备份
pg_dump -U postgres -h localhost -Fc -Z 9 mydb > /backup/db_full_$(date +%Y%m%d).dump

# 并行备份
pg_dump -U postgres -h localhost -Fc -j 4 mydb > /backup/db_parallel.dump

# 逻辑备份（SQL格式）
pg_dump -U postgres -h localhost -Fp mydb > /backup/db_sql_$(date +%Y%m%d).sql

# 备份所有数据库
pg_dumpall -U postgres -h localhost > /backup/all_databases.sql

MySQL备份

#!/bin/bash
# mysql-backup.sh

# 全量备份
mysqldump -u root -p --all-databases --single-transaction \
  --routines --triggers --events | gzip > /backup/mysql_full_$(date +%Y%m%d).sql.gz

# 只备份特定数据库
mysqldump -u root -p mydb --single-transaction > /backup/mydb_$(date +%Y%m%d).sql

# 使用xtrabackup（物理备份）
xtrabackup --backup --target-dir=/backup/xtrabackup_$(date +%Y%m%d)

MongoDB备份

#!/bin/bash
# mongodb-backup.sh

# 使用mongodump
mongodump --uri="mongodb://localhost:27017" \
  --out=/backup/mongodb_$(date +%Y%m%d) \
  --gzip

# 备份特定数据库
mongodump --uri="mongodb://localhost:27017/mydb" \
  --out=/backup/mydb_$(date +%Y%m%d)

文件系统备份

rsync备份

#!/bin/bash
# rsync-backup.sh

# 本地备份
rsync -avz --delete \
  /home/ \
  /backup/home/

# 远程备份
rsync -avz --delete \
  /home/ \
  user@remote-server:/backup/home/

# 使用增量备份
rsync -avz --delete --link-dest=/backup/latest \
  /home/ \
  /backup/incremental/$(date +%Y%m%d)/

# 更新latest链接
ln -sfn /backup/incremental/$(date +%Y%m%d) /backup/latest

使用Borg备份

#!/bin/bash
# borg-backup.sh

REPO="/backup/borg-repo"
ARCHIVE_NAME="home-$(date +%Y%m%d-%H%M%S)"

# 初始化仓库
borg init --encryption=repokey $REPO

# 创建备份
borg create \
  --stats \
  --progress \
  --compression lz4 \
  $REPO::$ARCHIVE_NAME \
  /home/ \
  /etc/ \
  /opt/app/config/

# 列出备份
borg list $REPO

# 清理旧备份
borg prune \
  --keep-daily=7 \
  --keep-weekly=4 \
  --keep-monthly=6 \
  $REPO

云存储备份

AWS S3备份

#!/bin/bash
# s3-backup.sh

# 上传备份到S3
aws s3 sync /backup/ s3://my-backups/$(date +%Y%m%d)/ \
  --storage-class STANDARD_IA

# 启用版本控制
aws s3api put-bucket-versioning \
  --bucket my-backups \
  --versioning-configuration Status=Enabled

# 设置生命周期策略
aws s3api put-bucket-lifecycle-configuration \
  --bucket my-backups \
  --lifecycle-configuration '{
    "Rules": [
      {
        "ID": "MoveToIA",
        "Status": "Enabled",
        "Transitions": [
          {
            "Days": 30,
            "StorageClass": "STANDARD_IA"
          },
          {
            "Days": 90,
            "StorageClass": "GLACIER"
          }
        ],
        "Expiration": {
          "Days": 365
        }
      }
    ]
  }'

配置备份策略

# backup-policy.yaml
backup_policy:
  production_database:
    type: "database"
    method: "pg_dump"
    frequency: "daily"
    retention: "30d"
    storage: "s3://backups/db/"
    encryption: true
    verification: true
    
  production_files:
    type: "filesystem"
    method: "borg"
    frequency: "daily"
    retention: "90d"
    storage: "s3://backups/files/"
    compression: "lz4"
    
  kubernetes_configs:
    type: "kubernetes"
    method: "kubectl"
    frequency: "hourly"
    retention: "7d"
    storage: "s3://backups/k8s/"

备份验证

自动化验证脚本

#!/bin/bash
# verify-backup.sh

BACKUP_FILE=$1
VERIFY_DIR="/tmp/verify_$$"
mkdir -p $VERIFY_DIR

echo "验证备份文件: $BACKUP_FILE"

# 1. 检查文件完整性
echo "检查文件完整性..."
if ! gzip -t $BACKUP_FILE; then
  echo "错误: 备份文件损坏"
  exit 1
fi

# 2. 解压验证
echo "解压备份文件..."
gunzip -c $BACKUP_FILE > $VERIFY_DIR/restored.sql

# 3. 语法检查
echo "检查SQL语法..."
psql -U postgres -f $VERIFY_DIR/restored.sql --set ON_ERROR_STOP=on 2>&1 | head -20

# 4. 数据验证
echo "验证数据..."
TABLE_COUNT=$(psql -U postgres -t -c "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'public';")
echo "表数量: $TABLE_COUNT"

# 清理
rm -rf $VERIFY_DIR
echo "备份验证完成"

定期验证计划

# verification-schedule.yaml
verification:
  daily:
    - "检查备份文件大小"
    - "验证备份完成状态"
    
  weekly:
    - "解压测试"
    - "SQL语法验证"
    
  monthly:
    - "完整恢复测试"
    - "数据一致性检查"
    
  quarterly:
    - "灾难恢复演练"
    - "备份策略审查"

备份监控

Prometheus监控

# prometheus-rules.yaml
groups:
  - name: backup-monitoring
    rules:
      - alert: BackupFailed
        expr: backup_status{job="backup"} == 0
        for: 1h
        labels:
          severity: critical
        annotations:
          summary: "备份任务失败"
          description: "{{ $labels.backup_type }} 备份失败"
      
      - alert: BackupOld
        expr: time() - backup_last_success_timestamp > 86400 * 2
        labels:
          severity: warning
        annotations:
          summary: "备份过期"
          description: "{{ $labels.backup_type }} 备份已超过2天未更新"

最佳实践

3-2-1规则: 3份副本，2种介质，1份异地
自动化: 备份过程完全自动化
加密: 备份数据必须加密
验证: 定期验证备份可恢复性
监控: 监控备份状态和完成情况
文档: 保持恢复流程文档更新