Oracle Database Appliance is an “always on” database system. It does not have to go down if a component fails. Component failures are accounted for and the configuration is built with redundancy and single point of failures in mind. Further, it is a very simple system to deploy and operate.
If you are familiar with Oracle technologies, then technically, the best way to look at the Oracle Database Appliance may be to think of it as a two node Oracle Linux RAC cluster in a single box with shared storage and networking all included in the box. It is built and configured with redundancy to achieve continuous availability in the event of component failures. It addresses all single points of failures within the system.
The current software stack (as of April, 2012) consists of Oracle Linux 5.8 (with the UEK kernel), Oracle Grid Infrastructure 184.108.40.206, and Oracle Database 220.127.116.11. On your Oracle Database Appliance, you can run Oracle RAC databases, Oracle Single Instance databases, or Oracle RAC One (active – passive) databases, or a combination of these.
Oracle Database Appliance is extremely simple to deploy. When you receive your appliance unit, you simply put the appliance in a computer rack, (or you can place it on a table, or in a closet), then you plug in the power and network connections to the Database Appliance and power on the Oracle Database Appliance. You then input the information for your configuration (system names, database names, database size, etc.) and for all practical purposes you just issue a single command to complete the deployment of your Oracle Database Appliance. That command is “oakcli deploy” that you issue from Linux system prompt. More on that will be covered later. The command initiates the entire process of setting up the OS, installing Oracle software, creating the initial database, and optionally setting up a cloud file system volume (a shared file system), configuring Oracle Auto Service Request, etc. as you watch the progress on your screen.
The multiple weeks’ worth of effort previously required in configuring an HA database is no longer necessary! The actual deployment process in fact takes less than one hour. And at the end of that one hour you have a fully functional cluster and a fully usable database available for your application to use.
Customers typically complete their deployments on the day they open the box and put the appliance in the rack. What is really interesting is the side benefit of this ease of use which results in lower chances of errors in configuration. The risks and uncertainties involved in setting up the HA system have virtually disappeared. And that means a lot for users. Now they can go ahead and buy an Oracle Database Appliance knowing that they can have a fully functional highly available database system on the day that it arrives!