备份压缩问题：备份文件压缩设置不当，导致备份失败

# 使用 gzip 压缩备份文件（默认压缩级别为 6）
tar -czf /backup/full_backup_20250207.tar.gz  /source/directory 
 
# 调整压缩级别（1-9，数字越大压缩率越高）
tar -czf /backup/full_backup_20250207.tar.gz  --use-compress-program="gzip -9" /source/directory 

# 使用 xz 压缩备份文件（默认压缩级别为 6）
tar -cJf /backup/full_backup_20250207.tar.xz  /source/directory
 
# 调整压缩级别（0-9，数字越大压缩率越高）
tar -cJf /backup/full_backup_20250207.tar.xz  --use-compress-program="xz -9" /source/directory

# 使用 zstd 压缩备份文件（默认压缩级别为 3）
tar -cf /backup/full_backup_20250207.tar.zst  --use-compress-program="zstd" /source/directory 
 
# 调整压缩级别（1-19，数字越大压缩率越高）
tar -cf /backup/full_backup_20250207.tar.zst  --use-compress-program="zstd -19" /source/directory

# 将大文件分割为小块
split -b 1G large_file.txt  large_file_part_
 
# 分别压缩每个小块
for part in large_file_part_*; do
    gzip "$part"
done 
 
# 合并并解压小块文件
cat large_file_part_*.gz | gunzip > large_file_restored.txt  

# 使用 tar 打包并分块压缩
tar -cf - /source/directory | split -b 1G - /backup/full_backup_20250207.tar.gz. 
 
# 合并并解压
cat /backup/full_backup_20250207.tar.gz.*  | tar -xzf -

# 检查磁盘空间
df -h
 
# 如果空间不足，清理旧备份
find /backup -type f -mtime +7 -exec rm {} \;

#!/bin/bash
 
# 定义变量
SOURCE_DIR="/source/directory"
BACKUP_FILE="/backup/full_backup_20250207.tar.gz" 
 
# 压缩备份文件
tar -czf $BACKUP_FILE $SOURCE_DIR 2>/var/log/compression_errors.log 
 
# 检查压缩是否成功
if [ $? -ne 0 ]; then
    echo "压缩失败，请检查日志" | mail -s "压缩告警" admin@example.com  
fi

# 生成 SHA256 校验值
sha256sum /backup/full_backup_20250207.tar.gz  > /backup/checksum.sha256 

# 验证 SHA256 校验值
sha256sum -c /backup/checksum.sha256 

#!/bin/bash
 
# 压缩并记录日志
compress_backup() {
    echo "开始压缩备份文件..."
    tar -czf /backup/full_backup_20250207.tar.gz  /source/directory 2>/var/log/compression_errors.log 
    if [ $? -eq 0 ]; then
        echo "压缩成功" >> /var/log/compression.log  
    else
        echo "压缩失败" >> /var/log/compression.log 
    fi 
}
 
compress_backup 

# 示例：压缩失败时发送告警邮件
if [ $? -ne 0 ]; then
    echo "压缩失败，请检查日志" | mail -s "压缩告警" admin@example.com 
fi