I'd like to distribute a Web application as a VM image in order to make distribution, installation and maintenance as easy as possible for customers (virtual appliance). This image should include everything software related (application, Web server, database, etc.). Since I cannot know how big the data is each customer is going to store I'd like to plug in storage separately.
Is there a standard way of providing an image where the customer at deployment time can add a volume that is, e.g., automatically mounted at a specific location that can then be used by my application? The best way would be for this working without having to log onto the virtual machine and manually mount volumes or something.
As for the format I'm thinking about the usual suspects VMDK and OVF if that's important.