Can you check POST Code(Overview -> Server -> Trouble Shooting-> Post Code) and Life Controller Logs(Overview -> Server -> Logs-> Lifecycle Logs) on iDRAC and check whether that have any information on failure?

Post code is stuck at 0x6 Multiprocessor initialization

Lifecycle logs:

other noteworthy lifecycle logs:
2021-04-19T18:42:43+0200 VDR7
Virtual Disk 1 on Integrated RAID Controller 1 has failed.

2021-04-19T18:42:43+0200 VDR7
Virtual Disk 0 on Integrated RAID Controller 1 has failed.

2021-04-27T12:04:07+0200 SUP1906
Firmware update successful.

2021-04-27T12:02:30+0200 SUP1905
Firmware update programming flash.

2021-04-27T12:02:30+0200 SUP1903
Firmware update verify image headers.

2021-04-27T12:01:57+0200 SUP1904
Firmware update checksumming image.

2021-04-27T12:01:57+0200 SUP1911
Firmware update initialization complete.

2021-04-27T12:01:56+0200 SUP1901
Firmware update initializing.

2021-04-21T19:09:14+0200 SUP0518
Successfully updated the PowerEdge BIOS firmware to version 2.12.1.

2021-04-21T19:06:10+0200 SUP0516
Updating firmware for PowerEdge BIOS to version 2.12.1.

Hello,

If it isn't allowing you to continue through POST at this point, I'd consider performing a power drain of the system, first. This would be accomplished by shutting the server off, unplugging it from the supply, then holding the power button down for ~10 seconds. You can then attempt to bring it back up as normal.

I'm not familiar with the error code you're seeing, though an image may provide the context needed to provide any further troubleshooting recommendations. 

The messages about the failed virtual disks wouldn't have anything to do with an inability to POST, though they could certainly prevent you from booting the OS. I'm not seeing anything in those entries that would stand out as a problem, aside from the virtual disk entries.

Hey DYlan,

I had already shut down and disconnected the system several times during previous testings (and to see if an actual cold boot makes a difference)

I just did it again, including 20 seconds of keeping the power button pressed, just to be sure.

the screen that comes up almost immediately on a warm boot shows the flashed BIOS, the rollback screen doesnt show any BIOS, the overview screen shows the old BIOS.

I put an intermediate BIOS update (to 1.5.6) through IDRAC on the system yesterday and did a warm boot, but it is still sitting in the queue as scheduled, the reboot job is showing as completed.

I will now complete the very cold boot and hope the actual BIOS upgrade job will start now!

after the cold boot, the scheduled BIOS upgrade job to 1.5.6 remains in the queue doing nothing.

But i did notice another thing, in my roll back overview the BIOS is back visible but the backplane 2.20 seems to have gone missing.

I now cleared the jobqueue and started a rollback job on 1.2.10 and hope the rollback actually gets initiated, afterwards I would attempt to go to idrac version that is available below and slowly upgrade through yearly BIOS version differences. (but that will remain a plan until we can solve this) 

After the cold boot the BIOS rollback job remains scheduled. I do see my upload of 1.5.6 sitting available now but any BIOS update or rollback job is stuck in the queue, probably because it is stuck on that POST screen?

Yes I think this is the reason. Can you verify where it is stuck?
Thanks

Marco

how can i verify this?

I can say the following:

1) racadm fwupdate -s sometimes gives the information that it is running, sometimes it doesnt

2) post code is stuck at 0x6 MultiProcessor Initialisation

3) sometimes in the iDrac the update and/or rollback pages will give an informational message that a firmware update is in progress

I have no idea on how to check 'where' it is stuck