rsync not copy all information for font file

[Ram Ballu]

Good morning list, 
this is my first question and hope really to get an answer, sorry for my bad english :-(

Ok so i have a machine with ubuntu and use as data server for my graphics works. 
Now i am trying to backup my folder on an external HDD using "rsync" where i save all my data file (file of graphics software, image, font etc.).
For this i mount HDD in local and launch command "rsync  -avz  source_folder  destination_folder.
I notice that in backup copy font file have zero kb size rather than 25-60 kb in source folder and i can't use the font from backup folder as it results zero kb.
Can someone help me to solve this issue.
Thanks in advance to all for reading this and spend your time.
Ram