Created attachment 229028 [details]
I have a TrueNAS 12 system (using FreeBSD 12 under the hood) which suddenly stopped booten with the message "KDB: debugger backends: ddb" (see attachements). The system is a Supermicro Server CSE-848X 4x 12C Xeon E7-4850 v2 2,3GHz 256GB ECC.
There was no update or anything done. After a regular shutdown it comes not up anymore. SLIT tables shoes my 4 NUMA nodes but then stops, going into a reboot cycle which then finally comes to hold / hang.
Does a verbose boot (select from the loader prompt) offer any insight?
(In reply to Ed Maste from comment #1)
The right side of the attached screehshot is already the verbose output. After the SLIT.Localities everythings stops. I was told that the next expected line would be the resolution of the console window. I tried to disable the redirction of the serial console, but it does not help.
Foud the issue.
Even if the memory passed the POST check, there were 3 defektive ECC DIMMs.
Issue found: defective memory