Isolated storage enables applications to create and maintain a safe client-side
virtual file system for partial trust applications. In Silverlight, all I/O
operations are restricted to isolated storage and do not use the file system of
the operating system.
With isolated storage, data is always isolated by the user in a virtual file
system that can be just one file in the root directory or a tree of directories
and files.
The isolated storage data compartment is an abstraction, not a specific storage
location. It consists of one or more isolated storage files, called stores,
which contain the actual directory locations where data is stored. Any kind of
data can be saved in the store.
Stores usually reside on the client but an application can also use isolated
storage on a server. However, Silverlight does not support roaming profiles that
enable information to travel with a user.
![IsoStorge1.gif]()
Figure
The above figure is the Silverlight Configuration dialog displayed when you
right click on the Silverlight plugin space and select "Silverlight", the above
dialog would be displayed.
![IsoStorge2.gif]()
Figure
The above figure is the configuration of Application Storage for specific sites
in terms of Quota.
Quota Groups
The amount of isolated storage available for an application to use depends on
the allocated space that the host domain can use on a particular client's
computer. This allocated space is called a quota group.
An application on a domain shares the quota group with all the other
applications on that domain. This enables multiple applications in the same
domain to share a single quota. Note that domain in this context refers to a
virtual host domain, such as Microsoft.com, not to an application domain.
A quota group's default size is 1 MB. An application can request to increase the
quota group size with the IncreaseQuotaTo method. If the user approves the
increased size, that size is the new quota group size that all applications on
that domain can share.