Data Guard based replication vs. SAN (EVA5000 & CA) based replication

Data Guard based replication vs. SAN (EVA5000 & CA) based replication

What are the pros and cons of Data Guard based replication vs. SAN (EVA5000 & CA) based replication?

    Requires Free Membership to View

    Login

    When you register for SearchStorage.com, you’ll also receive targeted emails from my team of award-winning editorial writers. Our goal is to keep you informed on the hottest topics, the latest news and the biggest challenges you face as a storage professional today.

    Rich Castagna, Editorial Director

    By submitting your registration information to SearchStorage.com you agree to receive email communications from TechTarget and TechTarget partners. We encourage you to read our Privacy Policy which contains important disclosures about how we collect and use your registration and other information. If you reside outside of the United States, by submitting this registration information you consent to having your personal data transferred to and processed in the United States. Your use of SearchStorage.com is governed by our Terms of Use. You may contact us at webmaster@TechTarget.com.

To answer this question, it must first be assumed that when you say EVA5000 and "CA," you are referring to and Oracle database stored on EVA5000 disk storage and replicated offsite using CA's XOsoft WANSynchHA for Oracle. When compared at a high-level, both methods offer similar features and much more than array based replication because they both are application aware. In comparison, simple disk array based replication requires extra steps to ensure that the database remains consistent during the replication process. For example, any type of "snapshot like" replication requires that the database be aware of the operation (typically briefly quiesced) to establish a clear point-in-time relationship with subsequent database changes (i.e.: redo logs). Some of the advantages of Data Guard over WANSynchHA include:
  • Synchronous replication (in addition to asynch)
    • .
  • Redo apply to a physical replica or SQL apply to a logical replica
    • .
  • Replication to up to nine standby databases
    • .
  • Offers the ability to choose between three protection modes (Maximum Protection, Maximum Availability and Maximum Performance) to fit specific business requirements
    • .
  • Seamless "role switching" from primary to standby between databases.
However, cost must be taken into consideration. Data Guard is part of Oracle Enterprise and, unless an organization is already licensed for Enterprise, can add significant implementation costs. It should also be noted that at this point, XOsoft WANSynchHA Oracle is a Windows-based solution. Oracle Data Guard runs on Oracle on supported platforms and integrates with Oracle RAC, Flashback and RMAN.

This was first published in December 2006