In the last few months, there’s been a big push by Oracle to talk to customers like me about the Exadata Database machine and the Exalogic Elastic Cloud machine. From talking with other DBAs and reading the blog posts, the systems seem to have amazing performance. Unfortunately, I don’t think I’m going to be playing with one any time soon because the systems don’t fit with my company’s requirements (or budget).
Price tag aside, one big “Do Not Pass Go” for us is the lack of data replication technology available at the hardware level. If my business requires the power of an Exadata or Exalogic, I think it’s a reasonable assumption that such programs are mission-critical and something I want to protect in case of a Disaster Recovery (DR) situation like an earthquake or fire that takes out my primary data center. Instead I’m forced to rely on database specific replication technologies like Data Guard. Acceptable if I’m running just databases, but what about Exalogic? Exalogic is “cloud in a box” – designed for application servers.
I’ve been looking around trying to find data on Exadata and Exalogic in DR situations and the data has been sparse, but I did come across a presentation by Rene Kundersma who works as a Database Technical Architect and Software Engineer for Oracle Consulting. If you recall, I took exception to something Rene to wrote in another blog entry, but the fact is Rene is an Oracle Certified Master (OCM) in 9i, 10g and 11g and Oracle RAC and Linux certified. I think we can safely say that Rene is an expert on these technologies and would know how best to ensure uptime.
In the presentation Oracle Database Machine at TUI: Business Case, Setup, Migration, and Experiences you can see that the entire Exadata DR/backup strategy involves another SAN and tape drives with a RTO to restore from tape of 2 hours. Of course, they also use Oracle Data Guard (a database specific technology) to replicate the databases to another Exadata, and that’s great if you want your databases to stay in sync (and can afford the licensing costs of all the database licenses on another Exadata), but what if you want the ability to bring up your DB at any point in time in the last X hours? You can, but you greatly increase the ability to quickly bring up the DR version with the latest system changes.
SAN Replication Technologies such as EMC’s Recoverpoint have had features like this for years along with others not in Data Guard and these technologies aren’t limited to just databases.