一、DM 备份文件基础认知：从概念到价值
1.1 什么是 DM 备份文件：定义与构成
DM 备份文件是达梦数据库 (DM Database) 在运行过程中，通过专用备份工具或 SQL 命令将数据库中的数据文件、控制文件、归档日志等核心数据按照特定格式封装后生成的物理或逻辑副本。它是数据库运维体系中保障数据安全、实现灾难恢复的关键产物。
从底层实现来看，DM 备份文件通常以 .bak 为后缀，配合 .meta 元数据文件共同组成完整的备份集。备份集中不仅记录了数据块的内容，还包含了备份时刻的数据库版本、SCN (System Change Number)、表空间结构等关键信息，确保恢复时能够还原到一致的状态。
1.2 DM 备份文件的核心特性：能力解析
DM 备份文件具备以下几个突出特性：
1.3 DM 备份文件的应用场景：价值落地
DM 备份文件广泛应用于以下典型场景：
二、DM 备份文件的生产流程：从配置到执行
2.1 环境准备与配置：前置条件
在生成 DM 备份文件前，需要完成以下准备工作：
开启归档模式的核心 SQL 如下：
ALTER DATABASE MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE ADD ARCHIVELOG 'DEST=/dm/data/arch, TYPE=LOCAL, FILE_SIZE=256, SPACE_LIMIT=2048';
ALTER DATABASE OPEN;
2.2 使用 DIsql 执行在线备份：核心流程
DIsql 是 DM 提供的命令行客户端，通过 BACKUP 语句可以生成 DM 备份文件。其工作流程如下：
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.edge-thickness-invisible{stroke-width:0;fill:none;}#publish-mermaid-1786942660488-0 .edge-pattern-dashed{stroke-dasharray:3;}#publish-mermaid-1786942660488-0 .edge-pattern-dotted{stroke-dasharray:2;}#publish-mermaid-1786942660488-0 .marker{fill:#333333;stroke:#333333;}#publish-mermaid-1786942660488-0 .marker.cross{stroke:#333333;}#publish-mermaid-1786942660488-0 svg{font-family:\”trebuchet ms\”,verdana,arial,sans-serif;font-size:16px;}#publish-mermaid-1786942660488-0 p{margin:0;}#publish-mermaid-1786942660488-0 .label{font-family:\”trebuchet ms\”,verdana,arial,sans-serif;color:#333;}#publish-mermaid-1786942660488-0 .cluster-label text{fill:#333;}#publish-mermaid-1786942660488-0 .cluster-label span{color:#333;}#publish-mermaid-1786942660488-0 .cluster-label span p{background-color:transparent;}#publish-mermaid-1786942660488-0 .label text,#publish-mermaid-1786942660488-0 span{fill:#333;color:#333;}#publish-mermaid-1786942660488-0 .node rect,#publish-mermaid-1786942660488-0 .node circle,#publish-mermaid-1786942660488-0 .node ellipse,#publish-mermaid-1786942660488-0 .node polygon,#publish-mermaid-1786942660488-0 .node path{fill:#ECECFF;stroke:#9370DB;stroke-width:1px;}#publish-mermaid-1786942660488-0 .rough-node .label text,#publish-mermaid-1786942660488-0 .node .label text,#publish-mermaid-1786942660488-0 .image-shape .label,#publish-mermaid-1786942660488-0 .icon-shape .label{text-anchor:middle;}#publish-mermaid-1786942660488-0 .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#publish-mermaid-1786942660488-0 .rough-node .label,#publish-mermaid-1786942660488-0 .node .label,#publish-mermaid-1786942660488-0 .image-shape .label,#publish-mermaid-1786942660488-0 .icon-shape .label{text-align:center;}#publish-mermaid-1786942660488-0 .node.clickable{cursor:pointer;}#publish-mermaid-1786942660488-0 .root .anchor path{fill:#333333!important;stroke-width:0;stroke:#333333;}#publish-mermaid-1786942660488-0 .arrowheadPath{fill:#333333;}#publish-mermaid-1786942660488-0 .edgePath .path{stroke:#333333;stroke-width:1px;}#publish-mermaid-1786942660488-0 .flowchart-link{stroke:#333333;fill:none;}#publish-mermaid-1786942660488-0 .edgeLabel{background-color:rgba(232,232,232, 0.8);text-align:center;}#publish-mermaid-1786942660488-0 .edgeLabel p{background-color:rgba(232,232,232, 0.8);}#publish-mermaid-1786942660488-0 .edgeLabel rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#publish-mermaid-1786942660488-0 .labelBkg{background-color:rgba(232, 232, 232, 0.5);}#publish-mermaid-1786942660488-0 .cluster rect{fill:#ffffde;stroke:#aaaa33;stroke-width:1px;}#publish-mermaid-1786942660488-0 .cluster text{fill:#333;}#publish-mermaid-1786942660488-0 .cluster span{color:#333;}#publish-mermaid-1786942660488-0 div.mermaidTooltip{position:absolute;text-align:center;max-width:200px;padding:2px;font-family:\”trebuchet ms\”,verdana,arial,sans-serif;font-size:12px;background:hsl(80, 100%, 96.2745098039%);border:1px solid #aaaa33;border-radius:2px;pointer-events:none;z-index:100;}#publish-mermaid-1786942660488-0 .flowchartTitleText{text-anchor:middle;font-size:18px;fill:#333;}#publish-mermaid-1786942660488-0 rect.text{fill:none;stroke-width:0;}#publish-mermaid-1786942660488-0 .icon-shape,#publish-mermaid-1786942660488-0 .image-shape{background-color:rgba(232,232,232, 0.8);text-align:center;}#publish-mermaid-1786942660488-0 .icon-shape p,#publish-mermaid-1786942660488-0 .image-shape p{background-color:rgba(232,232,232, 0.8);padding:2px;}#publish-mermaid-1786942660488-0 .icon-shape .label rect,#publish-mermaid-1786942660488-0 .image-shape .label rect{opacity:0.5;background-color:rgba(232,232,232, 0.8);fill:rgba(232,232,232, 0.8);}#publish-mermaid-1786942660488-0 .label-icon{display:inline-block;height:1em;overflow:visible;vertical-align:-0.125em;}#publish-mermaid-1786942660488-0 .node .label-icon path{fill:currentColor;stroke:revert;stroke-width:revert;}#publish-mermaid-1786942660488-0 .node .neo-node{stroke:#9370DB;}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node rect,#publish-mermaid-1786942660488-0 [data-look=\”neo\”].cluster rect,#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node polygon{stroke:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].swimlane.cluster rect{filter:none;}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node path{stroke:#9370DB;stroke-width:1px;}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node .outer-path{filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node .neo-line path{stroke:#9370DB;filter:none;}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node circle{stroke:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].node circle .state-start{fill:#000000;}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].icon-shape .icon{fill:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942660488-0 [data-look=\”neo\”].icon-shape .icon-neo path{stroke:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942660488-0 :root{–mermaid-font-family:\”trebuchet ms\”,verdana,arial,sans-serif;}是否
启动 DIsql 连接数据库
检查数据库状态为 OPEN
执行 BACKUP DATABASE 语句
是否指定压缩加密
按参数生成压缩加密备份
生成普通备份
写入 .bak 与 .meta 文件
记录备份集到控制文件
输出备份完成信息
执行库级完全备份的示例：
BACKUP DATABASE FULL TO "DB_FULL_20250101" BACKUPSET '/dm/backup/DB_FULL_20250101';
执行增量备份时，需要指定基备份目录：
BACKUP DATABASE INCREMENT WITH BACKUPDIR '/dm/backup/DB_FULL_20250101' TO "DB_INCR_20250102" BACKUPSET '/dm/backup/DB_INCR_20250102';
2.3 使用 dmrman 工具管理备份：日常运维
dmrman 是 DM 专用的备份恢复管理工具，可在数据库关闭状态下对 DM 备份文件进行查看、校验、删除等操作。
查看备份集信息：
./dmrman CTLSTMT="SHOW BACKUPSET '/dm/backup/DB_FULL_20250101'"
校验备份集是否可用：
./dmrman CTLSTMT="CHECK BACKUPSET '/dm/backup/DB_FULL_20250101'"
删除过期备份集：
./dmrman CTLSTMT="REMOVE BACKUPSET '/dm/backup/DB_FULL_20250101'"
通过 dmrman 还能将备份集导出为跨平台传输格式，便于在不同操作系统间迁移 DM 备份文件。
三、DM 备份文件的恢复实践：从策略到落地
3.1 完全恢复流程：标准操作
当数据库发生故障需要从 DM 备份文件恢复时，完全恢复是最直接的方式。整体恢复流程如下：
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circle,#publish-mermaid-1786942661268-1 .node ellipse,#publish-mermaid-1786942661268-1 .node polygon,#publish-mermaid-1786942661268-1 .node path{fill:#ECECFF;stroke:#9370DB;stroke-width:1px;}#publish-mermaid-1786942661268-1 .rough-node .label text,#publish-mermaid-1786942661268-1 .node .label text,#publish-mermaid-1786942661268-1 .image-shape .label,#publish-mermaid-1786942661268-1 .icon-shape .label{text-anchor:middle;}#publish-mermaid-1786942661268-1 .node .katex path{fill:#000;stroke:#000;stroke-width:1px;}#publish-mermaid-1786942661268-1 .rough-node .label,#publish-mermaid-1786942661268-1 .node .label,#publish-mermaid-1786942661268-1 .image-shape .label,#publish-mermaid-1786942661268-1 .icon-shape .label{text-align:center;}#publish-mermaid-1786942661268-1 .node.clickable{cursor:pointer;}#publish-mermaid-1786942661268-1 .root .anchor path{fill:#333333!important;stroke-width:0;stroke:#333333;}#publish-mermaid-1786942661268-1 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.state-start{fill:#000000;}#publish-mermaid-1786942661268-1 [data-look=\”neo\”].icon-shape .icon{fill:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942661268-1 [data-look=\”neo\”].icon-shape .icon-neo path{stroke:#9370DB;filter:drop-shadow(1px 2px 2px rgba(185, 185, 185, 1));}#publish-mermaid-1786942661268-1 :root{–mermaid-font-family:\”trebuchet ms\”,verdana,arial,sans-serif;}通过异常
确认故障范围
关闭数据库实例
准备目标 DM 备份文件
使用 dmrman 执行 RESTORE
执行 RECOVER 应用归档日志
执行 RECOVER DATABASE UPDATE DB_MAGIC
启动数据库并验证数据
数据一致性检查
恢复完成
排查日志并重新恢复
恢复操作的关键命令：
./dmrman CTLSTMT="RESTORE DATABASE '/dm/data/DAMENG/dm.ini' FROM BACKUPSET '/dm/backup/DB_FULL_20250101'"
./dmrman CTLSTMT="RECOVER DATABASE '/dm/data/DAMENG/dm.ini' FROM BACKUPSET '/dm/backup/DB_FULL_20250101'"
./dmrman CTLSTMT="RECOVER DATABASE '/dm/data/DAMENG/dm.ini' UPDATE DB_MAGIC"
3.2 增量备份与恢复策略：周期方案
在大数据量场景下，频繁执行完全备份会消耗大量资源，因此通常采用 "一次完全 + 多次增量" 的备份策略。增量恢复时，dmrman 会自动识别基备份与增量备份的依赖关系，按顺序逐层应用。
推荐的备份策略周期如下：
增量恢复示例：
./dmrman CTLSTMT="RESTORE DATABASE '/dm/data/DAMENG/dm.ini' WITH BACKUPDIR '/dm/backup' FROM BACKUPSET '/dm/backup/DB_INCR_20250102'"
3.3 异地恢复与容灾演练：兜底保障
为验证 DM 备份文件的有效性，运维团队应定期在异地环境进行恢复演练。异地恢复的核心要点包括：
通过定期演练，可以及时发现备份链路中的隐患，真正发挥 DM 备份文件在数据安全体系中的兜底作用。
