Explanation/Reference:
Explanation:
Once you identify candidate grid disks, use the CREATE DISKGROUP command to create your ASM disk groups.
Here are some of the more important considerations to think about when creating ASM disk groups on Exadata:
* (A) When capacity planning, take your redundancy specification into consideration. Normal redundancy will have the effect of reducing your usable storage to half the raw capacity, and high redundancy will shrink it to a third of your raw disk capacity.
* Simplicity is best on Exadata. Using wild-carded CREATE DISKGROUP syntax not only offers the most terse command syntax, but also ensures your ASM disk groups are spread evenly across your Exadata Storage Server disks.
* Take the time to plan grid disk prefix names and overall grid disk configuration in the context of your desired ASM disk group design.
* Make sure to set the appropriate compatible.asm and compatible.rdbms attributes when creating ASM disk groups.
* Whenever possible, use a 4 MB extent size when creating disk groups on ASM storage.