How I can change the caracteristic do filesystem /alzenir of JFS para EJFS(large file)? What is the procedure.
In two words: you can't!
The bad news is: you can't change this property of a filesystem, because it would mean a completely different organization of the filesystem datastructures.
The only option you have is to back up the filesystems content, delete it, recreate it and restore the data. I hate to have no better news for you, but this is definitely the only way.
bakunin