When applying updates on Exadata systems, database server updates are automatically rolled back to a working state on a previous release if the update fails. This ensures that the system can be restored to a working state in the event of a failed update. Additionally, storage server updates are also automatically rolled back to a previous release in the event of a failed update.
This is documented in the Oracle Exadata Database Machine X9M Implementation Essentials official text book and more information can be found on the Oracle support website [1][2].

Oracle Exadata X9M-2 supports virtualization through Kernel-based Virtual Machine (KVM), enabling multiple virtual machines (VMs) to run on each database server. Specifically:
Each X9M-2 database server can support up to 12 virtual guests. This number provides ample flexibility for running various applications or Oracle Real Application Clusters (RAC) instances across virtualized environments .
While Exadata X9M-8 supports even more extensive virtualization, this question focuses on the X9M-2 model. The specified limitation of 12 guests per database server considers both system resource allocation and performance optimization .

1. ZFS Storage Appliance (ZFSSA) can’t connect directly to the Exadata 100Gb RoCE network switches. ZFSSA uses Fibre Channel protocol to connect to the Exadata storage cells. C. When backing up multi-rack systems, sharing Exadata X9M switches is not recommended. Each rack should have its own switches to minimize the risk of data loss due to switch failure.
Review the safety guidelines.
Unpack Oracle Exadata Rack.
Let the Exadata acclimatize for 24 hours.
Place Exadata in its allocated space.
Stabilize the Exadata Rack.
Power on Exadata PDU A.
Power on Exadata PDU B.
This order ensures that the necessary safety precautions are taken before installing the Exadata Database Machine, and that the machine is allowed to acclimate to its new environment before being powered on.

According to the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book, the maximum DRAM capacity you can expand an X9M-2 DB Server is 1024GB. This is the maximum amount of DRAM that can be installed in the server. The specific steps for adding DRAM are outlined in the book and can be referenced here: https://docs.oracle.com/cd/E80920_01/E80920/html/x9m_hardware_memory.html.

Oracle KVM Guest: This is a virtual machine that runs on top of Oracle Linux KVM hypervisor. It can be used to run Oracle Database or other applications on Exadata Database Machine2. Therefore, it runs on the Database Servers.
Oracle Enterprise Manager Agent (OMA): This is a software agent that communicates with Oracle Enterprise Manager Cloud Control and provides monitoring and management capabilities for Exadata Database Machine2. Therefore, it runs on both Database Servers and Storage Servers.
ASM instance: This is an instance of Oracle Automatic Storage Management (ASM), which is a volume manager and a file system for Oracle Database files. It manages disk groups that span across multiple Storage Servers2. Therefore, it runs on the Database Servers.
RDBMS instance: This is an instance of Oracle Database that processes SQL statements and executes transactions. It uses ASM disk groups to store data files, control files, redo log files, etc2. Therefore, it runs on the Database Servers.
Automatic Diagnostic Repository Command Interpreter (ADRCI): This is a command-line tool that enables you to view diagnostic data stored in the Automatic Diagnostic Repository (ADR). ADR is a file-based repository for database diagnostic data such as trace files, alert logs, etc2. Therefore, ADRCI runs on both Database Servers and Storage Servers, depending on where the ADR is located.
CELLCLI: This is a command-line interface that enables you to configure and manage Exadata Storage Server Software. It allows you to perform tasks such as creating disk groups, monitoring cell health, applying patches, etc2. Therefore, it runs on the Storage Servers.
Cell Server(CELLSRV): This is a process that runs on each Storage Server and handles I/O requests from the Database Servers. It implements Exadata Smart Scan , which offloads data-intensive SQL operations from the Database Servers to the Storage Servers2. Therefore, it runs on the Storage Servers.
diskmon: This is a process that monitors the status of disks and flash devices on each Storage Server. It reports disk failures and performs automatic disk reclamation2. Therefore, it runs on the Storage Servers.
Restart Server (RS): This is a process that manages automatic restarts of critical processes such as CELLSRV , MS , or OMA in case of failures. It also handles graceful shutdowns and startups of all processes on each server2. Therefore, it runs on both Database Servers and Storage Servers.
Management Server (MS): This is a process that provides management services for each server such as collecting metrics , logging events , executing commands from CELLCLI , etc2. Therefore, it runs on both Database Servers and Storage Servers

For a non-virtual deployment of Oracle Exadata with a single cluster:
Single Client Access Name (SCAN) Listeners: By default, three SCAN listeners are configured on the RDMA over Converged Ethernet (RoCE) network. This setup allows for load balancing and high availability of incoming client connections across the cluster nodes.
Oracle Cluster Registry (OCR) Multiplexing: The OCR is typically stored in multiple locations within the disk groups to enhance reliability and fault tolerance. On Exadata, the OCR is multiplexed across the DATA and RECO disk groups for enhanced resilience.
ora.diskmon Resource: This is an essential component of Oracle Clusterware, responsible for monitoring and managing disk-related cluster resources. It is always enabled and kept online by Oracle Clusterware on Exadata systems.

For database servers, perform a server backup using patchmgr -dbnodes dblistfile -backup -rolling. This is according to the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book . The other statement is false as exachk should not be used to resolve warnings or errors [1], but rather to identify them so that they can be addressed. Additionally, patchmgr should not be used with the –autofix, –autobackup, –upgrade, or –rolling flags as this could cause unexpected issues.

According to the web search results123, the storage servers in an Exadata Database Machine are mainly used for processing data at the storage level and offloading some SQL operations from the database servers. Therefore, the two activities that are supported on the storage servers are:
1. changing the root password
2. configuring secure shell user equivalency for the cellmonitor user
https://docs.oracle.com/en/engineered-systems/exadata-database-machine/dbmso/exadata-introduction.html

RoCE, or Remote Direct Memory Access over Converged Ethernet, is a high-speed networking technology that allows data to be transferred between servers, storage, and other devices over Ethernet. Persistent Memory is a form of non-volatile memory that can be used to store data without losing it when power is lost.
Oracle Linux 8.0 supports both RoCE and Persistent Memory, allowing Exadata systems to leverage the benefits of both technologies. For more information on Oracle Linux 8.0 and its features, refer to the Oracle Exadata Database Machine X9M Implementation Essentials official text book and resources.

The dbmcli -e “LIST IBPORT DETAIL” command is not valid on Exadata X9M. According to the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book [1][2], this command is only valid on Exadata X3 and X4 models. The other three commands are valid on Exadata X9M.

Failure groups provide redundancy in Oracle Exadata Database Machine X9M by ensuring that mirror copies of the data are written to different storage servers [1][2]. This prevents the potential for mirror copies to be written to the same server, which would cause a data loss if that server were to experience a physical disk failure. Furthermore, failure groups help to ensure that the ASM Flex instances are enabled on a maximum of two database servers or VMs per cluster, providing an extra layer of data protection. Additionally, Extended Redundancy mirrors data across data centers, providing the highest levels of data protection. Reference: Oracle Exadata Database Machine X9M Implementation Essentials [1][2], Chapter 5: Configuring Oracle ASM.