Questions to Determine

• Is the BMC event log showing the reboots as OS-initiated or hardware-initiated power cycles?
• Are there any thermal events (CPU, inlet, exhaust temperature warnings) preceding the reboots?
• Is the PSU event log clean, or are there power fault/loss events?
• Does mcelog show uncorrectable memory errors (UCEs), not just correctable ones?
• Is the BIOS configured to reboot on UCE, or does it halt?
• Could the CMOS battery be failing, causing intermittent BIOS instability?
• Are there any firmware bugs known for this iDRAC/BIOS version that cause spurious reboots?
• Is there a hardware watchdog timer that could be triggering the reboot?
• Have the power cables and PDU outlets been checked for intermittent contact?
• Is kdump configured and functional? If so, why are no crash dumps being generated?