Avamar grids require hardware and operating system homogeneity. All nodes within a single multi-node server must be of the same hardware generation and run the same OS. Avamar Gen4 servers exclusively use SUSE Linux Enterprise Server (SLES). The presence of Gen3 nodes is an unsupported hardware mix. Furthermore, some nodes running Red Hat Enterprise Linux (RHEL) is an unsupported OS configuration for a Gen4 system. Therefore, the installation cannot proceed until the hardware and software are standardized to Gen4 nodes running SLES.

B. Re-kickstarting the RHEL nodes to SLES would not resolve the core issue of having an unsupported mix of Gen3 and Gen4 hardware in the same grid.

C. This is incorrect as Gen4 hardware requires SLES, not RHEL. This action would also fail to resolve the unsupported hardware generation mix.

D. This is incorrect because Avamar Gen4 servers are standardized on SLES, not RHEL. It also fails to address the mixed-generation hardware issue.

1. Dell EMC Avamar Administration Guide, P/N 302-005-475 REV 01, 2019, Page 39: "All data nodes in an Avamar multi-node server must be of the same Dell hardware generation."

2. Dell EMC Avamar Gen4S Hardware and Security Overview and Hardening Guide, 2016, Page 6: "The Avamar Gen4S hardware platform runs on SUSE Linux Enterprise Server 11 SP3 (SLES11SP3)." This establishes the OS standard for Gen4 hardware.

3. Dell Avamar 7.5.1 for VMware System Installation Guide, P/N 302-004-203 REV 01, 2018, Page 15: "All nodes in a multi-node server must be of the same type."