SLE15 is a VM for a customer. the TW systems I cannot provide anymore as they are all fixed and the reload of the ucode stuff does not trigger the iissues after the fix which let my collegue and I think of this: if ucode (intel/amd) is there, it triggers a specific initrd build that b0rks the system. (ref comment #8). If there is no ucode installed --> no another dracut run, basically) If you then update the system, putting back and doing a dracut -f does not fail anymore. What I can do is checking out if I can find back both ISOs (TW) and redo this in a VM. re 23031107 to 20231108 -- happened on a vm (vmware workstation) in windows (intel) and on two physical systems (laptops, also intel) the base image 15.5 we used for the customer (SLE) booted fine and failed after the update. we luckily had a snapshot so when we went back, removing ucode there (intel) and udated, all was fine. So our idea is that there is somewheren between versions/updates there is a specific condition that breaks the booting process. Give me some time to find the specific snapshots and replay this in a workstation vm. Re SLE: we can definitely 'replay' this from the base image and update but think the rdsosreport could be a problem. We'll see.