Moving an on-premises RHEL 9 VM to EC2 with VM Import failed twice: first on the VMDK format, then on GRUB. Once the AMI finally booted, it had no network. Here is the pre-flight checklist we now run on every guest before uploading a disk.
We swapped Docker for rootless Podman on a small RHEL host and the stack failed twice: rootlessport refused port 80, then PostgreSQL could not write its bind-mounted data directory. Both come from running without root: unprivileged ports, user namespaces and SELinux labels.
After a Tuesday dnf update, image uploads on our Rocky Linux PHP servers returned 500s. A repository update moved ImageMagick to a new library version, and our hand-built imagick extension still linked to the old one. How we found it in dnf history, rolled back, pinned versions and made updates boring again.