Starting with Exadata

It comes in a rack with the components that make up a database infrastructure: disks, servers, networking gear, and so on. Three configuration types are available: (1) full rack, (2) half rack, or (3) quarter rack. The architecture is identical across all three types but the number of components differs.

The following list applies to a full rack:

• Database Nodes– The Exadata Database Machine runs Oracle Database 11g Real Application Cluster. The cluster and the database run on the servers known as database nodes or compute nodes (or simply “nodes”). A full rack has 8 nodes running Oracle Linux or Oracle Solaris.
• Storage cells– The disks are not attached to the database compute nodes, as is normally the case with the direct attached storage, but rather to a different server known as the storage cell (or just “cell”; there are 14 of them in a full rack). The Oracle Exadata Server Software runs in these cells on top of the OS.
• Disks– each cell has 12 disks. Depending on the configuration, these disks are either 600GB high performance or 2TB high capacity (GB here means 1 billion bytes, not 1024MB). You have a choice in the disk type while making the purchase.
• Flash disks– each cell also has 384GB of flash disks. These disks can be presented to the compute nodes as storage (to be used by the database) or used a secondary cache for the database cluster (called smart cache).
• Infiniband circuitry– the cells and nodes are connected through infiniband for speed and low latency. There are 3 infiniband switches for redundancy and throughput. Note: there are no fiber switches since there is no fiber component.
• Ethernet switch– the outside world can communicate via infiniband, or by Ethernet. There is a set of Ethernet switches with ports open to the outside. The clients may connect to the nodes using Ethernet. DMAs and others connect to the nodes and cells using Ethernet as well. Backups are preferably via infiniband but they can be done through network as well.
• KVM switch– there is a keyboard, video, and mouse switch to get direct access to the nodes and cells physically. This is used initially while setting up and when the network to the system is not available. In a normal environment you will not need to go near the rack and access this KVM, not even for powering on and off the cells and nodes.

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