Any size limitation on root files?

I am sorting data and creating xxx.root file which contains a TTree. And I found whenever the xxx.root file size was reaching 2GB, xxx.root switched to xxx_01.root automatically and soon my program crashed. I am sure that my system doesn’t have 2 GB limition, so why did it happen? Is it because of any size limitation from ROOT? Is there any way to get rid of limitation?

Thank you very much!

Read carefully … ChangeFile