Many organizations rely on databases to process and track operations, sales, logistics, and other activities vital to their continued viability. For this reason, it’s essential that you include database recovery techniques in your disaster recovery plans. It’s a wise idea to have a database specialist on the DRP team who can provide input as to the technical feasibility of various ideas. After all, you shouldn’t allocate several hours to restore a database backup when it’s impossible to complete a restoration in less than half a day!
许多组织依靠数据库来处理和跟踪运营、销售、物流和其他对其持续生存能力至关重要的活动。出于这个原因，你必须在你的灾难恢复计划中包括数据库恢复技术。在DRP团队中配备一名数据库专家是一个明智的想法，他可以为各种想法的技术可行性提供意见。毕竟，当你不可能在不到半天的时间内完成恢复工作时，你不应该分配几个小时的时间来恢复数据库备份!（不会乱规划）
In the following sections, we’ll cover the three main techniques used to create offsite copies of database content: electronic vaulting, remote journaling, and remote mirroring. Each one has specific benefits and drawbacks, so you’ll need to analyze your organization’s computing requirements and available resources to select the option best suited to your firm and within the boundaries of your RPO. Selecting solutions that lose data beyond your RPO pose unwarranted risk, whereas selecting those that are more aggressive than your RPO may incur unnecessary costs.
在下面的章节中，我们将介绍用于创建数据库内容异地拷贝的三种主要技术：电子保险箱、远程日记和远程镜像。每一种都有具体的好处和缺点，所以你需要分析你的组织的计算要求和可用资源，以选择最适合你的公司并在RPO范围内的选项。选择那些丢失数据超过RPO的解决方案会带来不必要的风险，而选择那些比RPO更积极的解决方案可能会产生不必要的成本。
1、Electronic Vaulting 电子保险箱/电子分批复制
In an electronic vaulting scenario, database backups are moved to a remote site using bulk transfers. The remote location may be a dedicated alternative recovery site (such as a hot site) or simply an offsite location managed within the company or by a contractor for the purpose of maintaining backup data.
If you use electronic vaulting, remember that there may be a significant delay between the time you declare a disaster and the time your database is ready for operation with current data. If you decide to activate a recovery site, technicians will need to retrieve theappropriate backups from the electronic vault and apply them to the soon-to- be production servers at the recovery site.
自动化技术按计划（通常是每天）将数据库备份从主数据库服务器移动到远程站点。
2、Remote Journaling 远程日志记录
With remote journaling, data transfers are performed in a more expeditious manner. Data transfers still occur in a bulk transfer mode, but they occur on a more frequent basis, usually once every hour and sometimes more frequently. Unlike electronic vaulting scenarios, where entire database backup files are transferred, remote journaling setups transfer copies of the database transaction logs containing the transactions that occurred since the previous bulk transfer.
有了远程日志，数据传输就能以更快的方式进行。数据传输仍以批量传输模式进行，但传输的频率更高，通常是每小时一次，有时更频繁。
Remote journaling is similar to electronic vaulting in that transaction logs transferred to the remote site are not applied to a live database server but are maintained in a backup device. When a disaster is declared, technicians retrieve the appropriate transaction logs and apply them to the production database, bringing the database up to the current production state.
远程日志与电子保险库类似，转移到远程站点的交易日志不应用于实时数据库服务器，而是保存在一个备份设备中。当宣布发生灾难时，技术人员会检索相应的交易日志并将其应用到生产数据库中，使数据库达到当前的生产状态。
3、Remote Mirroring 远程镜像
Remote mirroring is the most advanced database backup solution. Not surprisingly, it’s also the most expensive! Remote mirroring goes beyond the technology used by remote journaling and electronic vaulting; with remote mirroring, a live database server is maintained at the backup site. The remote server receives copies of the database modifications at the same time they are applied to the production server at the primary site. Therefore, the mirrored server is ready to take over an operational role at a moment’s notice.
远程镜像是最先进的数据库备份解决方案。毫不奇怪的是，它也是最昂贵的! 远程镜像超越了远程日志和电子保险箱所使用的技术；通过远程镜像，在备份站点保持一个实时数据库服务器。远程服务器在数据库修改应用到主站点的生产服务器的同时，也会收到这些修改的副本。因此，被镜像的服务器准备好在任何时候接管一个操作角色。
Remote mirroring is a popular database backup strategy for organizations seeking to implement a hot site. However, when weighing the feasibility of a remote mirroring solution, be sure to take into account the infrastructure and personnel costs required to support the mirrored server, as well as the processing overhead that will be added to each database transaction on the mirrored server.
对于寻求实施热站点的组织来说，远程镜像是一种流行的数据库备份策略。然而，在权衡远程镜像解决方案的可行性时，一定要考虑到支持镜像服务器所需的基础设施和人力成本，以及将添加到镜像服务器上的每个数据库交易的处理费用。
参考文档：
CISSP第九版英文版OSG
