https://docs.oracle.com/en/engineered-systems/exadata-database-machine/dbmmn/maintaining-exadata-storage-servers.html#GUID-AE16A1DA-53C6-4E80-94E5-963AA65373AB

According to the Oracle documentation1, two monitoring tools that might be useful in examining I/O performance for the prod database are:
cellcli (or exacli/exadcli) to examine storage server metrics such as database, category, ceiidisk, and griddisk (D). This tool can help you monitor the I/O Resource Management (IORM) metrics and identify any bottlenecks or imbalances in the storage layer.
I/O-specific dynamic performance views such as v$iostat_fiie, v$iostat_function, and v$iostat_consumer_group from the prod database instances using SQL *plus. These views can help you monitor the I/O activity and latency at the file, function, and consumer group level.

The two actions that are not appropriate for monitoring how a large production table is accessed in order to leverage the benefits of the Exadata Platform are A) querying VSSYSTEMEVENTS and filtering for the event 'cell physical IO interconnect bytes returned by smart scan', associated to your table; and B) querying v$segmentstatistics and filtering for the Object ID of your table from dbaobjects and the the column STATISTICNAME='optimized physical reads'. Instead, you should query v$SYSTAT and filter for the statistic 'cell smart table scan', associated to your table (C), or run the CellCli-command list activerequest, filtering for the attributes ioReason and objectNumber, that you specify as 'Smart Scan' and the Object ID of your table from DBA_OBJECTS (D). These two methods are outlined in the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book (Chapter 8, Monitoring the Exadata Database Machine).

Exadata Secure RDMA Fabric isolation is a feature that allows you to use virtualization on the X9M-2 platform while maintaining security and isolation between multiple tenants or VM clusters. Secure Fabric isolation works by creating a dedicated network partition and VLAN ID for each Database VM cluster, which is used for cluster networking between the database servers in the VM Cluster. This ensures that the network traffic of each VM cluster is isolated from the others, and it prevents unauthorized access to the data or resources of other VM clusters. Secure Fabric isolation can also be used for other purposes such as client networking, Data Guard traffic, but it's mainly used to provide security and isolation between multiple tenants or VM clusters.
According to Oracle's documentation1, Exadata Secure RDMA Fabric Isolation is a feature that enables strict network isolation for Oracle Real Application Clusters (Oracle RAC) clusters on Exadata Database Machine systems that use RDMA over Converged Ethernet (RoCE). Exadata Secure RDMA Fabric Isolation uses RoCE VLANs to ensure that network packets from one VM cluster cannot be seen by another VM cluster. VLAN tag enforcement is done at the KVM host level, which means that security cannot be bypassed by any software exploits or misconfiguration on the database server VMs1.
Therefore, the statement that is true about how Exadata Secure RDMA Fabric isolation is used in X9M-2 with virtualization enabled is:
With Secure Fabric isolation, each Database VM cluster uses a dedicated network partition and VLAN ID for cluster networking between the database servers in the VM Cluster. This provides security and isolation between multiple tenants or VM clusters.

To drop all celldisks on all the storage servers in an X9M-2 quarter rack, you should use the CELLADMIN account, which has the necessary privileges to perform this task. You can use the CELLCLI command-line interface to drop the celldisks. The best way to do this is by calling CELLCLI on all cells using DCLI (Oracle Database Command Line Interface) which allows you to run commands on multiple servers at once. Alternatively, you can use an administrator-created storage server user with appropriate privileges on celldisk objects by calling CELLCLI on all cells using exadcli. It is not recommended to use the CELLMONITOR account, as it has a more limited set of privileges. It is also important to note that EXACLI is not a valid tool for this task
https://docs.oracle.com/en/engineered-systems/exadata-database-machine/dbmmn/maintaining-exadata-storage-servers.html