Grid disk vs ASM Disk group

Oracle ASM disk groups with Oracle Exadata Storage Server grid disks. It represents a typical, but simplified configuration, that can be used as a model for building larger Oracle Exadata Storage Server grids with additional storage cells and disks.

This Oracle Exadata Storage Server grid illustrates the following:

• The storage cells in the grid use an InfiniBand network to connect to the database servers that have a single-instance database or Oracle Real Application Clusters (Oracle RAC) database installation.
• Each storage cell is composed of physical disks.
• Each cell disk represents a physical disk and a LUN.
• Each cell disk is partitioned into grid disks.
• Oracle ASM disk groups are set up to include the grid disks.

Oracle ASM failure groups are created to ensure that files are not mirrored on the same storage cell to tolerate the failure of a single storage cell. The number of failure groups equals the number of Exadata Cells. Each failure group is composed of a subset of grid disks in the Oracle ASM disk group that belong to a single storage cell.