The master.vmp file is the master version map that contains the GUIDS for all of the objects and the version of each object that currently exists on the server.
When the server starts, it looks at the master.vmp file and attempts to find each of the objects referenced in the file. If there are objects in the data directory that don't have a corresponding GUID in master.vmp, those objects are deleted. If the master.vmp doesn't exist when the server starts, the server creates a new master.vmp file and deletes all of the objects in the data directory.
If you lost the master.vmp file, then everything in the data directory will be deleted from the data directory, and there is no way to recover the database unless you either have a current backup of the database OR have a copy of the database project as it existed on the server.
Support Engineer, Microsoft SQL Server
Karan ... I know this is an old post. I'm hoping you are still receiving updates. I'm in a situation where it appears that my master.vmp file was re-created because it did not see the original master.vmp. Therefore the data directory was deleted as you indicated on this article. I have a copy of the original data directory from several days ago. You indicated that if this folder exist, there is a chance we can recover the database. If this is possible, I am more than happy to compensate you for your help in recovering our database. Please let me know and I will send you my phone number and or email address.