In a multi X-Brick XtremIO X1 cluster, the failure of more than half of the COM (communication) cables forces the cluster into a degraded mode. This degraded mode is a protective measure to ensure that the cluster can continue operating with reduced performance and redundancy until the issues with the COM cables are resolved.

In Dell XtremIO X2 arrays, the Disk Protection Groups (DPGs) are organized in such a way that each DPG spans multiple rows of drives. Specifically, DPG-2 in an XtremIO-X2 DAE (Disk Array Enclosure) uses the drives in Row 1 and Row 2. This configuration is designed to ensure redundancy and fault tolerance. The drives in these rows collectively form the DPG, which is responsible for data protection and performance optimization.

For an XtremIO X2-S, the ports used on the InfiniBand switches for an Inter-Switch Link (ISL) connection are typically high-numbered ports, which are usually at the end of the port range on the switch. While the specific port numbers can vary depending on the switch model and configuration, ports 35 and 36 are commonly used for ISL connections in many configurations1.
The process to identify the ISL ports is as follows:
Access the InfiniBand switch via the management interface.
Use the appropriate command to list the port configuration (this command can vary based on the switch's firmware).
Identify the ports configured for ISL, which will be indicated in the port configuration settings.
It's important to refer to the official Dell XtremIO Maintenance Achievement document or the InfiniBand switch documentation for the exact port numbers as they can differ based on the switch model and the cluster configuration1.

ESRS (EMC Secure Remote Services) configuration verification is typically done using commands that check for system notifications and configurations.
The show-syslog-notifier command is used to verify the settings and configuration of syslog notifications, which is part of the ESRS setup.
This command helps in ensuring that the notifications are correctly configured and functioning as intended, allowing for remote monitoring and management.

An extra rack unit space is used between X-Bricks when installing a multi X-Brick XtremIO X2 to accommodate the cable management duct. This space is essential for organizing and managing the cables, ensuring proper airflow, and making maintenance tasks easier.