From the following article - How to Prepare a Trading Account for Migration to Virtual Hosting
Migration is transferring the current active environment from the client terminal to the virtual one. This is a simple and straightforward way to change the set of launched programs, open charts and subscription parameters in the virtual terminal.
Migration is performed during each synchronization of the client terminal. Synchronization is always a one-direction process - the client terminal's environment is moved to the virtual terminal but never vice versa. The virtual terminal status can be monitored via requesting the terminal's and Expert Advisors' logs as well as virtual server's monitoring data.
To perform synchronization, execute "Synchronize Environment" command and select migration type.
Thus, you always can change the number of charts and the list of symbols in the Data Window, the set of launched programs and their input parameters, the terminal settings and Signal subscription.
When performing migration, all data is recorded in the client terminal's log.
After the synchronization, open the virtual terminal's main journal to examine the actions performed on it.
In the newly opened log window, you can set a piece of text the journal entries are to be filtered by and a desired interval. After that, click Request to download the found logs.
Virtual terminal logs themselves are updated at each request and saved in <terminal data folder>/logs/hosting.<hosting_ID>.terminal and <terminal data folder>/logs/hosting.<hosting_ID>.experts.