http://www.asp.net/identity/overview/extensibility/overview-of-custom-storage-providers-for-aspnet-identity

gistfile1.cs

[Plugin]
public class StartupPlugin : Plugin, IStartup
{
    private static readonly ILog Log = LogManager.GetLogger(typeof (StartupPlugin));

    /// <summary>
    /// Startup class for MiNET. Example sets the user and role managers and stores 
    /// for the application.
    /// </summary>
    /// <param name="server"></param>
    public void Configure(MiNetServer server)
    {
        server.UserManager = new UserManager<User>(new DefaultUserStore());
        server.RoleManager = new RoleManager<Role>(new DefaultRoleStore());
        Log.Info("Executed startup successfully. Replaced identity managment.");
    }
}