1z0-902 Sample Questions Answers

According to Oracle’s documentation1, the Cell Control Command-Line Interface (CellCLI) utility is the command-line administration tool for Oracle Exadata System Software. It can be used to perform various tasks on Exadata Storage Servers, such as creating and managing objects, monitoring performance, and configuring alerts.

To run CELLCLI commands on multiple cells simultaneously, you can use the Distributed Command-Line Interface (dcli) utility2. The dcli utility allows you to execute commands or scripts on a group of cells or hosts in parallel. You can use the dcli utility to copy files from one cell or host to multiple cells or hosts using the -f option3. You can also use the dcli utility to execute commands or scripts on multiple cells or hosts using the -l option to specify a user name and the -g option to specify a file containing a list of cells or hosts3.

Therefore, to achieve your requirement of running a script with several CELLCLI commands on each cell in your Exadata full rack simultaneously, you must:

Copy and execute the script on all storage servers using the dcli command.

Oracle Linux 7.9 is the minimum version required to support RoCE and Persistent Memory. This is because Oracle Linux 7.9 includes kernel enhancements that enable RDMA over Converged Ethernet (RoCE) networking and Intel Optane DC Persistent Memory Modules (DCPMM) for Exadata X8M systems3. These features allow faster access latency and higher throughput for database workloads2.

According to the Oracle Exadata Database Machine documentation12, two recommended configuration best practices for backup and recovery on Exadata are:

A. Placing the backup network on dedicated switches installed in the top of the rack (ToR) has the benefits of isolating the backup network from other workloads and providing a greater level of control.

D. When off-site long-term backup retention is needed, use Oracle Database Backup Cloud Service as a low-cost, offsite scalable storage for a disaster recovery solution.

Exadata System Software metrics and alerts work as follows:

Persistence of Thresholds: When metric thresholds are configured, they remain active and persist across server reboots. This ensures consistent monitoring behavior even after maintenance or unexpected reboots .

Default Metrics: By default, metrics are collected without predefined thresholds. Administrators must set custom thresholds to enable specific alerting based on their operational requirements​.

To enable REST access to the MS process, you need to manually enable the REST services on each storage server by running the command cellcli -e "ALTER CELL ENABLE REST" and then configure authentication and authorization to ensure secure access. This is described in detail in the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book (Chapter 8, Securing the Exadata Database Machine).

https://docs.oracle.com/en/cloud/paas/exadata-cloud/csexa/access-rest-api.html

Option C shows the number of read hits from PMEM cache on storage servers which indicates how much data was served from PMEM instead of flash or disk1.

Option E shows detailed information about PMEM cache such as size, utilization, hit ratio, read latency and write latency2.

According to Oracle documentation1, Exadata Storage software has a complete set of automated operations for hard disk maintenance, when a hard disk has failed or has been flagged as a problematic disk. It will initiate a rebalance operation to redistribute data across other disks and mark the failed disk with an amber light.

This SQL statement is adding the new griddisks to the existing diskgroup "DATA" and creating one new failgroup, consisting of all 96 griddisks. The "REBALANCE POWER 512" option tells the system to perform a rebalance operation with a power of 512. It means the system distributes the data evenly across all the disks in the diskgroup using a power of 512.

The Oracle Exadata Deployment Assistant Command Line Interface (OEDACU) supports a variety of configuration and lifecycle management tasks for Exadata systems, such as adding or removing nodes, resizing ASM disk groups, and managing Oracle Database home directories. However, it does not support lifecycle management for the Zero Data Loss Recovery Appliance (ZDLRA), as this device requires different management tools specific to its backup and recovery functions .

The given command uses a for loop with ipmitool to issue ping commands sequentially to a range of IP addresses in the management network:

for j in {01..23}; do ipmitool sunoem cli "set /SP/network/test ping=192.168.1.1$j"; done

This script verifies the connectivity of the ILOM management network before the Exadata installation. Each server’s Service Processor (SP) is tested for reachability, confirming that the management network setup is operational across the full rack .

C. OEDA deployment steps include calibrate cells, create cell disks, and resecure machine2.

D. OEDA sets up key-based authentication for the root user by using the setuprootssh.sh utility included with OEDA2.

The two valid reasons are:

corruption in the / (root) filesystem . According to 1, this is one of the scenarios that requires a storage server rescue procedure , because it prevents the storage server from booting up normally . The rescue procedure will re-image the root filesystem with a fresh copy of the operating system and restore the configuration files from a backup1.

the failure of both physical M.2 disks . According to 2, each Exadata Storage Server X9M-2 has two physical M.2 disks that store the operating system and configuration files for the storage server . If both M.2 disks fail , then the storage server cannot boot up or function properly . The rescue procedure will replace the failed M.2 disks with new ones and re-image them with the operating system and configuration files2.

A. YOU query VSSYSTEM_EVENTS and filter for the event ‘cell physical IO interconnect bytes returned by smart scan’, associated to your table. This does not show how much data was filtered by Smart Scan, but only how much data was returned after Smart Scan12.

C. You query v$SYSTAT and filter for the statistic ‘cell smart table scan’, associated to your table. This does not show how much data was filtered by Smart Scan for a specific table, but only for all tables in a session12.

https://www.databasejournal.com/oracle/monitoring-smart-scans-in-oracle-exadata/

Once the physical disk has been replaced, you will need to create a new celldisk and griddisks on the replaced physical disk. After the griddisks have been dropped from the associated ASM diskgroups, you can then add the griddisks back into the ASM diskgroup they used to be a member of and rebalance the data on the effected griddisks. Finally, you should verify that the griddisks located on the physical disk have been successfully dropped from the associated ASM diskgroups.

This command is based on the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book and other resources. This command sets the power state of the system to ON and starts the storage server. It is the only command that is able to start the storage server remotely. All the other commands are incorrect or require the user to be physically present in the data center.

According to the Oracle Auto Service Request (ASR) documentation1, ASR raises service requests for qualified Oracle products that are detected with specific faults. The qualified Exadata products include2:

Database servers

Storage servers

InfiniBand switches

Cisco switches (X8M and later systems)

Power distribution units (PDUs)

According to Oracle’s documentation12, ASM failure groups provide redundancy by storing mirror copies of data on different disks or storage servers. When ASM allocates an extent for a normal redundancy file, ASM allocates a primary copy and a secondary copy. ASM chooses the disk on which to store the secondary copy so that it is in a different failure group than the primary copy1. This way, if one disk or storage server fails, ASM can still access the data from another failure group2.

Therefore, the statement that is true about how ASM failure groups provide redundancy is:

Failure groups contain all ASM disks in a single storage server preventing mirror copies being written to the same storage server.

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.

Oracle ASR covers a range of hardware components on Exadata Database Machines to ensure rapid response and issue resolution. The covered hardware components include critical parts such as:

Fan Trays: These are essential for cooling Exadata components and are covered by ASR in case of failures​.

System Controller (SC): Integral to the operation of Exadata storage servers, SC failures are reported by ASR to ensure the overall system’s reliability and availability​.

I/O Boards: ASR actively monitors and responds to failures in I/O boards, which are crucial for data processing and connectivity within Exadata storage servers​.

The ASR system is optimized to handle hardware-related issues proactively, ensuring that critical components are continuously monitored and replaced as necessary.

According to Oracle’s documentation12, some of the statements that are true about applying updates on Exadata systems are:

Failed storage server updates are automatically rolled back to a previous release1.

When running a “yum update” for a new Exadata release, all other repositories should be disabled1.

For adding a new RAC (Real Application Clusters) VM cluster to an existing Oracle Exadata X9M-2 deployment, you can utilize the Oracle Exadata Deployment Assistant (OEDA). OEDA is available in two interfaces:

OEDA Web-based Configuration Tool: This web-based interface facilitates the configuration of Exadata environments, supporting both physical and virtual deployments. The graphical interface helps in defining VM clusters, including RAC clusters, and ensures the configuration aligns with Oracle best practices​.

OEDA Command Line Interface (CLI): For more advanced or automated tasks, the command-line interface (oedacli) allows for precise control over the deployment process. It supports various configuration actions such as adding or removing clusters, resizing ASM disk groups, and managing VM clusters​.

These tools are specifically designed for Exadata configurations and provide a streamlined approach for deploying and managing RAC clusters in both physical and virtualized environments.

According to the Oracle Exadata Database Machine X9M-2 Data Sheet1, each PDU has two power input cables that can be connected to separate power sources for redundancy. However, if only one power source is available per PDU, then a single cable can be used to provide sufficient power for normal operation.

https://www.oracle.com/a/ocom/docs/engineered-systems/exadata/exadata-x9m-2-ds.pdf