[ymse]

I'm going to guess that these are Dell R730xd boxes with PERC H730 Mini controllers (LSI MegaRAID SAS-3 3108).

A failed/failing drive present during cold boot could cause the controller to believe there were no drives present. To add insult to injury, on early BIOS versions this made the UEFI interface inaccessible. The only way to recover from this state was to re-seat the RAID controller.

There were also two bizarre cases where the operating system SSD RAID1 would be wiped and replaced with a NTFS partition after upgrading the controller firmware (and more) on an affected system (hanging/flapping drives). Attempts to enter UEFI caused a fatal crash, but reinstall (over PXE) worked fine. BIOS upgrade from within fresh install restored it.

From the changelog:

    Fixes: 
    - Decreased latency impact for passthrough commands on SATA disks
    - Improved error handling for iDRAC / CEM storage functions
    - Usability improvements for CTRL-R and HII utilities
    - Resolved several cases where foreign drives could not be imported
    - Resolved several issues where the presence of failed drives could lead to controller hangs
    - Resolved issues with managing controllers in HBA mode from iDRAC / CEM
    - Resolved issues with displayed Virtual Disk and Non-RAID Drive counts in BIOS boot mode
    - Corrected issue with tape media on H330 where tape was not being treated as sequential device
    - resolved an issue where Inserted hard drives might not get detected properly.