Installing and upgrading help

AFAIK, Barracuda format it's a must, the differences about these 2 row formats it's explained here:

https://dev.mysql.com/doc/refman/5.6/en/innodb-file-format.html

If you don't convert your tables, the primary risk it's about the clipping of the values in some fields, which cannot store long variable-length data.

BTW the correct conversion direction is "Antelope to Barracuda..." and in the admin/moodleadmin directory you should find all the cli tools needed to check/fix your database engine/format.

As per moodle's requirements, its a recommended option and not required. Will come handy when restoring/backing up large courses.  Almost 80% cases wont even need it, but it annoys me to see amber colored warnings on moodle environment, therefore I convert them.