Seattle Academy has a very active Moodle 1.9 site with many custom extensions and potential legacy issues with it's database. I needed to do the following to update from the latest 1.9.8 to 2.0:
1. From the 1.9.8 backup, I deleted the wiki module. There were too many problems during update that prevented it from completing.
2. In version 2.0 preview 1, commented out line 61 of /mod/assignment/db/upgrade.php that begins $pbar->update. We have 750,000 assignment submissions. This line causes the browser doing updates to run out of memory at about 50,000 assignment submissions.
3. Comment out line 1936 of /lib/db/upgrade.php.
dbman->change_field_notnull($table, $field);
This was creating a fatal exception with our collection of blocks.
4. Change line 2612 of /lib/db/upgrade.php from $admins = get_admins(); to $admins = null. It was throwing an exception as it was not able to get_admins, perhaps since a login was not required (or permitted) to upgrade.
This allowed us to begin testing.
