EXADATA Overview, Configuration and Architecture

 

EXADATA Overview, Configuration and Architecture

What is Exadata?

Oracle Exadata Database Machine is a combined Compute(DB server) and Storage(Cell) system optimized for running Oracle Database software. 

Exadata Servers as per its Hardware  Configuration:

 Exadata Machine:

 

 

 

Architecture:

 

 

•LIBCELL

 LIBCELL, which is a library that is linked with the Oracle kernel. LIBCELL has the code that knows how to request data via iDB protocal.

•CELLSRV

Cell Services (cellsrv) is the primary software that runs on the storage cells. It is a multi-threaded program that services I/O requests from a database server.

•Management Server(MS)

MS is a Java program that provides the interface between cellsrv and the Cell Command Line Interface (cellcli) utility. MS also provides the interface between cellsrv and the Grid Control Exadata plug-in .

•Restart Server(RS)

RS is actually a set of processes that is responsible for monitoring the other processes and restarting them if necessary

•Input/Output Resource Manager(IORM)

 IORM manages I/O at the storage cell by organizing incoming I/O requests into queues according the database name, category, or consumer group that initiated the request. It then services these queues according to the priority defined for them in the resource plan.

•Infiniband Switches 
 InfiniBand switches and cables to form a 40 Gb/second InfiniBand fabric for database server to Exadata Storage Server communication, and RAC internode communication.

 

 

•Cellinit.ora and Cellip.ora
After Oracle Exadata Storage Server is configured, the database server host must be configured with the cellinit.ora and the cellip.ora files to use the cell. 

The files are located in the /etc/oracle/cell/network-config directory of the database server host.These configuration files contain IP addresses, not host names.




cellinit.ora - This file contains the database IP addresses.

cellip.ora -    This file contains the storage cell IP addresses.

Example:

Quarter RAC Exadata machine contains 2 compute(DB) nodes  and 3 Cell(Storage) servers.Below picture shows the ip configurations. 

192.168.50.23 and 192.168.50.24 belongs to Compute Nodes.

192.168.51.27, 192.168.51.28 and 192.168.51.29 belongs to Cell Servers.