M365 SharePoint OneDrive considerations

When you are setting up your M365 SharePoint sites and looking at the Document Libraries,  one of the things you will need to think about is are you going to allow OneDrive to sync it.

If so there are somethings you need to plan and think about if you do.  the first being that if a single Library is over 100K files this will greatly impact performance on OneDrive (and is also not recommended) and if the Total number of Libraries synced to the client is over 300K files again it will massively impact performance.

OneDrive Sync is there for offline file access not a replacement for a servers file share if you do wish to use it like this, do so via the Web interface with Office hooked in to it will give better mileage.

For the libraries that you allow to be cached offline keep them below 100K files and use non offline libraries for most of you data.

Also  even if you just sync a folder within the Library it does not matter the whole Library is taken in to account when syncing.

https://docs.microsoft.com/en-us/office365/servicedescriptions/sharepoint-online-service-description/sharepoint-online-limits