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by lunarg on April 22nd 2015, at 12:25

There are limitations to using OneDrive for Business to synchronize items.

Maximum items* for OneDrive for Business20 000
Maximum items* per Sharepoint document library5 000**

* Files and folders.
** You can synchronize more than one library.

Maximum size per item2 GB
Maximum name length for files and foldersSharepoint Server 2013: max. 128 chars
Sharepoint Online: max. 256 chars
Folder names: max. 250 chars
Maximum combined names (files and folders, aka "path": max. 250 chars
Invalid characters:\ / : * ? " < > | &hash;
spaces are not supported
files starting with a ~
Invalid chars (Sharepoint Server 2013):All of the above +
{ } % ~
names starting with a .
Unsupported folder names:forms at the top-level, or names starting with _vti_
Unsupported file names:GUID-names are not supported (e.g. {9b6634a7-26b7-40a2-a48e-6f967d89c29e}
Invalid file types (extensions)*.tmp
.DS_Store
desktop.ini
thumbs.db
ehtthumbs.db
all types blocked by your site administrator.
OneNote notesOneNote resources cannot be synced through OneDrive for Business, as they use their own mechanism for synchronizing contents.

Additionally, files locked (read or read/write locks) cannot be synced until the lock is released (i.e. files are closed).