URGENT - Issues with OneDrive & SharePoint Files-On-Demand sync and 100% disk usage

[NetWin]

We are in the middle of a migration and hit a wall, please help!!

We scrubbed data before successfully migrating to 6 sites in SharePoint OnLine the largest Site being about 350Gig.  Set up the permissions as necessary and started the Files-On-Demand option, mapped the user directories to OneDrive and initialized the sync on each of the 72 out of 150 devices.  There are also a few devices with large SSD’s where the full sync is set up.

Everyone has newer Dells with W10Pro, versions from the Creators Addition or 1903, most have the latest sync client.

Connectivity is good and this client has 4 locations, plus 10 remote offices, so no real bottlenecks.

The Files-On-Demand is showing activity and syncing-

But the sync is constant, the numbers of the files are always increasing, which makes the device hit a 100% disk usage, thus these 72 people cannot work.

Another issue, a user just created a doc, saved it on their desktop, it is taking about 3 hours for the file to show up.

When you close the OnDrive sync, the usage lowers a bit, then in about a half hour, it decreases to  50%

[#2]

OneDrive FoD shouldn't be constantly syncing. The whole idea is that it syncs when you open them, not as one whole job. Unless you've specifically told it to make the library always available.

Have you got any of the bandwidth restriction GPOs applied? It sounds like it is syncing a whole library.

With the latest OneDrive, you can specify libraries to always be online-only meaning it will never sync. I've found this useful for large collaboration areas where versioning may become an issue should people make changes offline etc that then conflict with online users changes.

[#3]

We have the latest client, we are syncing the entire library site for authorized users with FoD, they don't have large SSD's.  I have done this thousands of times and for some reason it will not stop trying to sync.

There must be some, non-apparent cause cascade failure occurring that maxes out activity of the disk .   @Rhys Williams 

[#4]

Even with FOD you should limit the total number of file synced locally to a total of 300 000 across all library and sites. If you pass that point you will have different sync issues and synching process could take hours! Train users and use FOB when needed and not has a standard way to go.

https://support.office.com/en-gb/article/invalid-file-names-and-file-types-in-onedrive-onedrive-for-...