After an OS upgrade, where is the old my.cnf file?

Question

After an OS upgrade, where is the old my.cnf file?

Answer

After an upgrade from CentOS to Almalinux, or between Ubuntu versions, for safety purposes a backup file is created with a different extension and the file will be placed in the same folder.

For CentOS to AlmaLinux conversions, the file may be renamed with the extension .rpmnew. More information can be found in the log files /var/log/yum.log or /var/log/dnf.log.

For Ubuntu, the file may be renamed with extension .dpkg-old or .dpkg-dist. More information can be found in the log file /var/log/dpkg.log.