I was trying to copy a VMware folder to the server's VMware share and I went offline.  After I finally rebooted to get things straightened out, I couldn't determine why my synchronization was taking a long time - well over 30 minutes.  I finally paid enough attention to see that it was trying to sync an offline copy of the main VMware disk image (about 4GB in size).  The problem is offline files was trying to keep a temporary copy of the file synched up until I deleted the temporary offline files.  When I deleted temporary offline files, it told me it deleted one file of 167MB but it freed up about 4GB on my C drive.