Exadata storage realms using ASM-scoped security mode allows you to control which database can access which griddisks by creating realms at the ASM level, thereby allowing you to limit the access of each database to the griddisks that it needs to access. This is covered in section 3.15.2 of the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book and Resources [1].

Exadata storage realms using database-scoped security mode allows you to control which database can access which griddisks by creating realms at the database level [1], thereby allowing you to limit the access of each database to the griddisks that it needs to access. This is covered in section 3.15.3 of the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book and Resources [2].

[1] https://docs.oracle.com/en/engineered-systems/exadata-database-machine/x9m/exad-implementing-database-machine-x9m.pdf  [2] https://docs.oracle.com/en/engineered-systems/exadata-database-machine/x9m/exad-implementing-database-machine-x9m.pdf

In order to monitor all components of this multirack configuration, Enterprise Manager agents must be deployed on at least two storage servers in both racks and all database servers in both racks. This is according to the Oracle Exadata Database Machine X9M Implementation Essentials official text book [1], in which it states "To monitor all components of the multirack configuration, you must deploy agents on all database servers and at least two storage servers in each rack" (page 6-15).

According to the Oracle documentation1, two statements that are true about enabling write-back flash cache are:

Write-back flash cache is on by default for High Capacity Storage Servers in High Redundancy configurations (A). This is because write-back flash cache provides better performance and reliability for data file writes than write-through flash cache.

Before write-back flash cache is enabled, you need to drop the Flash Cache first (D). This is because changing the flash cache mode requires recreating the flash cache with a different configuration.

According to 1, Exadata X9M-2 Database Servers are based on Intel Xeon Platinum 8368Y processors with 32 cores and 768 GB of DRAM memory per server. This memory can be expanded up to 1.5 TB per server by adding 24 x 32 GB DIMMs. The DRAM memory is used for buffer cache, PGA, and other database purposes1. Exadata X9M-2 Database Servers also have 25.6 TB of Persistent Memory Acceleration (PMEM) per server, which is used for log writes and columnar data caching1. PMEM is a new type of memory that combines the speed of DRAM with the persistence of flash2. Exadata X9M-2 Database Servers are designed to run Oracle Database workloads with high performance, scalability, and reliability2

The statements that are true about the CellCLI command are:

It has command-line history . According to 1, you can use the up and down arrow keys to scroll through previous commands that you entered in CellCLI . You can also use Ctrl+R to search for a previous command by entering part of it .

It can be executed on storage servers . According to 1, you can invoke CellCLI by logging in to the Exadata cell as cellmonitor , celladmin , or root user and typing “cellcli” . Within CellCLI , you can perform various management and monitoring tasks for the cell134.

It can be executed using the DCLI utility . According to 5, DCLI (distributed CLI) is another utility that can be used to execute scripts and commands across multiple storage cells from a single interface. You can use DCLI to run CellCLI commands on multiple cells at once54.

According to Oracle’s documentation1, the client network on Exadata X9M-2 Database Server is used for client access to the database servers using Single Client Access Name (SCAN) and Oracle RAC Virtual IP (VIP) addresses. To verify that the client network is available via both client switches, you can use the command:

cat /proc/net/bonding/bondeth0

This command displays information about the bondeth0 interface, which is used for the client network on Exadata X9M-2 Database Server2. You can check if both interfaces (eth0 and eth1) are active and connected to different switches3.

The Exadata X9M-2 Extended (XT) Storage Server does not include any Persistent Memory (PMEM) DIMMs. The XT server configuration primarily serves as a cost-effective archival storage option and lacks the performance features available in the HC (High Capacity) and EF (Extreme Flash) storage servers. This configuration does not include Persistent Memory, which is leveraged in other models for accelerating OLTP workloads and providing extremely low-latency data access​​.