I have done a successful migration of 1.5.3 courses with 100% Japanese into version 1.6beta5. Initially, it did not work in the following two cases.
- courses added after doing unicode migration
- courses based on 1.4.5 directly into 1.6
I reported this to Eloy at this
bug report 5276, and he recommended the following process.
- upgrade your site to 1.5.3+ (actually Eloy recommends a fresh install, I just upgraded)
- backup each of your 1.5.3 courses
- upgrade the site to 1.6
- do the unicode migration (this can only be done once)
- backup your courses once again in 1.6
I followed these steps, and it worked, Note I told the migration when prompted that all of my courses were based on the "ja" language pack. Note also, that you
*cannot* later add more 1.5.3 ja courses to the 1.6 site. They must go through the database migration process
which can only be done once. Thus, if you have an old 1.5.3 course that you wish to add at a later time after you already migrated, you cannot add it directly. As a workaround, you must make a new, separate 1.5.3 site, transfer your course into it, then upgrade that site into 1.6, backup the course, and move it into the intended 1.6 site. Voila!
You can see Eloy's further documentation at
this location in the Moodle Docs Wiki. Especially look for comments on non-ISO 8859-1 backups.
Cheers. Don