About ORAM initalization and running out of space I have two questions about ORAM


Since at the beginning,the server allocates unused storage for ORAM cient,there are no user's data in the storage.if now client access the storage the server will know that client is writing data except that the client read empty block to achieve oblivious.some paper mention that using a third trust party to initialize the ORAM. or just deem that the client itself have finish initilization and upload the storage to server. so how ORAM client initialize the storage?
All papers I read about ORAM scheme fixed the capacity at the begin of setup,that's not fitting into the real situation. since client's data will increase with time. Are there any scheme to increase ORAM storage with time while maintaining oblivious?
Are there any scheme to increase ORAM storage with time while maintaining oblivious?


I found this paper that addresses the issue of obliviously resizing:


Moataz, Tarik, Travis Mayberry, Erik-Oliver Blass, and Agnes Hui Chan. "Resizable tree-based oblivious RAM." In Financial Cryptography and Data Security, pp. 147-167. Springer Berlin Heidelberg, 2015.


I also recall a talk by Elaine Shi where she discussed resizable ORAM, but I can't find the relevant paper.