Scenario: Needed to change the primary domain name of a user from one domain to another.
The user also wanted to continue using OneDrive for Business Sync Client (for Windows).
Experience: Changed the users primary domain name in the 365 portal. Re-setup Outlook profile and also the users iPhone.
Regarding OneDrive for Business, once the primary domain was changed the OneDrive for Business URL did not update straight away. This took roughly 4-6 hours to update. Once the URL updated, all of the data was automatically moved to the new URL path. I then had to stop syncing the old path and resync the new URL path in the sync tool. This of course meant downloading all of the data. I figured this would be quicker then trying to wipe out the data in the cloud and re-uploading all of the data.
20,000 sync file limit?: Later my client discovered he could not sync more then 20,000 files with the windows sync client. This is an actual limitation with the sync client. I have discovered Microsoft are working on releasing an updated version of the sync client later this year. The sync client will also support large files up to 10GB, and allow selective folder sync. There is likely a preview version out at the moment.
Update to El Capitan: Updated from Yosemite to El Capitan. The OneDrive for Business sync client (preview) does not work at all. Office 2016 is also randomly crashing.