? ? ? ? ? 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!

? ? ? 許多組織依靠數(shù)據(jù)庫來處理和跟蹤運(yùn)營、銷售、物流和其他對其持續(xù)生存能力至關(guān)重要的活動。出于這個原因，你必須在你的災(zāi)難恢復(fù)計劃中包括數(shù)據(jù)庫恢復(fù)技術(shù)。在DRP團(tuán)隊中配備一名數(shù)據(jù)庫專家是一個明智的想法，他可以為各種想法的技術(shù)可行性提供意見。畢竟，當(dāng)你不可能在不到半天的時間內(nèi)完成恢復(fù)工作時，你不應(yīng)該分配幾個小時的時間來恢復(fù)數(shù)據(jù)庫備份!（不會亂規(guī)劃）

? ? ? ? ?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.

? ? ? ?在下面的章節(jié)中，我們將介紹用于創(chuàng)建數(shù)據(jù)庫內(nèi)容異地拷貝的三種主要技術(shù)：電子保險庫、遠(yuǎn)程日記和遠(yuǎn)程鏡像。每一種都有具體的好處和缺點(diǎn)，所以你需要分析你的組織的計算要求和可用資源，以選擇最適合你的公司并在RPO范圍內(nèi)的選項。選擇那些丟失數(shù)據(jù)超過RPO的解決方案會帶來不必要的風(fēng)險，而選擇那些比RPO更積極的解決方案可能會產(chǎn)生不必要的成本。

1、Electronic Vaulting? ?電子保險箱/電子分批復(fù)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.

自動化技術(shù)按計劃（通常是每天）將數(shù)據(jù)庫備份從主數(shù)據(jù)庫服務(wù)器移動到遠(yuǎn)程站點(diǎn)。

2、Remote Journaling 遠(yuǎn)程日志記錄

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.

有了遠(yuǎn)程日志，數(shù)據(jù)傳輸就能以更快的方式進(jìn)行。數(shù)據(jù)傳輸仍以批量傳輸模式進(jìn)行，但傳輸?shù)念l率更高，通常是每小時一次，有時更頻繁。

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.

遠(yuǎn)程日志與電子保險庫類似，轉(zhuǎn)移到遠(yuǎn)程站點(diǎn)的交易日志不應(yīng)用于實時數(shù)據(jù)庫服務(wù)器，而是保存在一個備份設(shè)備中。當(dāng)宣布發(fā)生災(zāi)難時，技術(shù)人員會檢索相應(yīng)的交易日志并將其應(yīng)用到生產(chǎn)數(shù)據(jù)庫中，使數(shù)據(jù)庫達(dá)到當(dāng)前的生產(chǎn)狀態(tài)。

3、Remote Mirroring? ?遠(yuǎn)程鏡像

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.

遠(yuǎn)程鏡像是最先進(jìn)的數(shù)據(jù)庫備份解決方案。毫不奇怪的是，它也是最昂貴的! 遠(yuǎn)程鏡像超越了遠(yuǎn)程日志和電子保險箱所使用的技術(shù)；通過遠(yuǎn)程鏡像，在備份站點(diǎn)保持一個實時數(shù)據(jù)庫服務(wù)器。遠(yuǎn)程服務(wù)器在數(shù)據(jù)庫修改應(yīng)用到主站點(diǎn)的生產(chǎn)服務(wù)器的同時，也會收到這些修改的副本。因此，被鏡像的服務(wù)器準(zhǔn)備好在任何時候接管一個操作角色。

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.

對于尋求實施熱站點(diǎn)的組織來說，遠(yuǎn)程鏡像是一種流行的數(shù)據(jù)庫備份策略。然而，在權(quán)衡遠(yuǎn)程鏡像解決方案的可行性時，一定要考慮到支持鏡像服務(wù)器所需的基礎(chǔ)設(shè)施和人力成本，以及將添加到鏡像服務(wù)器上的每個數(shù)據(jù)庫交易的處理費(fèi)用。

參考文檔：

CISSP第九版英文版OSG