Explanation/Reference:
A: Each disk in the Exadata storage cell is divided into equal sized pieces called storage regions (default
1MB). There is an index entry for every storage regions (1MB of data stored on disk). Each entry contains the minimum and maximum value for columns seen in 'where' clause predicates. Information for up to 8 columns can be stored. The index is then used to eliminate disk IO by identifying which storage regions don't match the 'where' clause of a query.

The exadcli utility facilitates centralized management across an Oracle Exadata system by automating the execution of ExaCLI commands.
Exadcli executes the commands on a set of remote nodes and returns the output to the centralized management location where the exadcli utility was run.
The exadcli utility runs commands on multiple remote nodes in parallel threads.

On both physical and virtual deployments, Exadata systems use minimal Linux distributions to ensure that just the RPMs needed to run Oracle database, are installed and enabled.
References:
http://www.oracle.com/technetwork/database/exadata/exadata-x5-2-ds-2406241.pdf

Explanation/Reference:
You can manage I/O resources based on categories by creating a category plan.
You can add any number of categories, or modify the predefined categories. You should map consumer groups to the appropriate category for all databases that use the same cell storage. Any consumer group without an explicitly specified category defaults to the OTHER category.
References: http://docs.oracle.com/cd/E80920_01/SAGUG/exadata-storage-server-iorm.htm

A: Exadata I/O Resource Manager (IORM) has been enhanced to enable or disable Smart Flash Logging for the different databases running on the Database Machine, reserving flash for the most performance critical databases.
B: The Exadata I/O Resource Manager (IORM) has been enhanced to enable or disable Smart Flash Logging for the different databases running on the Database Machine.
C: Smart Flash Logging works as follows. When receiving a redo log write request, Exadata will do parallel writes to the on-disk redo logs as well as a small amount of space reserved in the flash hardware. When either of these writes has successfully completed the database will be immediately notified of completion. If the disk drives hosting the logs experience slow response times, then the Exadata Smart Flash Cache will provide a faster log write response time.
Conversely, if the Exadata Smart Flash Cache is temporarily experiencing slow response times (e.g., due to wear leveling algorithms), then the disk drive will provide a faster response time.
This algorithm will significantly smooth out redo write response times and provide overall better database performance.