Welcome to the MongoDB Community Forums @Philipp_Kolbe !
The likely reason for encountering an illegal instruction is that your CPU does not meet the x86_64 microarchitecture requirements for MongoDB 5.0.
Can you please:
- Provide the output of
/proc/cpuinfo - Confirm if your Ubuntu is running in a VM and if so, the host O/S and VM software versions
Related discussion for someone trying to run MongoDB 5.0 on VirtualBox: Could not start MongoDB 5.0 running Oracle Linux on VirtualBox.
Thanks,
Stennie