Tuesday, February 22, 2011

Configuring an Exadata (part I)

I am getting ready to do a presentation on "real world Experiences" with the exadata, and I am still in process of getting the Exadata set up. I figured I would share some of the pain we are having getting the configuration checklist ready for ACS (advanced Customer Support).. This service comes with your Exadata, and the ACS folks configure the box by installing the OS, and the database software. They even set up a starter database. This is where the fun begins. The exadata is a beast of a box. Remember in a full rack there is 8 database nodes, and 14 storage servers. Switches, power supplies.. And to support all this it needs lots and lots of IP's, and lots and lots of "names" for these pieces. When setting up an Exadata you get 4 characters for a name. For many datacenters, it is hard to get descriptive in those 4 characters, and fitting it all into 4 characters might not follow your standards. This is very rigid because of the "one" script.. If you've never heard that term, it is the "one" script that installs everything. Think of it as the silent install for the whole Exadata box.. Everything is driven off of it.. Server names, Cell disk names.. EVERYTHING. If you to add it up, there are probably 200+ items in an exadata that need to be named with this script (thus the reason why the 4 character name is so important).

Same with the database. Oracle crates a simple UTF8 database. Nothing more. And they create dbcontrol within the Exadata, nothing more.

If you are prepared it should be pretty simple to set up.

I think this is where the difference lies between the Exadata and a true appliance. An appliance, you wheel it in, hook it up and run.. An Exadata, you need to give some thought to how to set it up. The Exadata gives you a lot of flexibility (you can run multiple applications and section them off across nodes), you can create indexes for OLTP type transactions, but with that flexibility comes more complexity. It's a trade off.

Continued in part 2


  1. How can I understat how is the connectivity between ASM and Exadata ?

  2. I'm not quite sure how the database server sees the luns. Traditionally I am used to changing permissions and stamping the luns. On the exadata the database servers and cells have config files that help them see each other. Once the grid disk is built with cellcli on a cell it is immediately visible from ASM. The discover path points to the location they mount on.