Access to COPY ORCHARD get 404:system.unauthorizedaccessexception:mappings.bin is denied

COPY ORCHARD get 404 error, results turn to look at logs, get the error is:

014-07-31 17:36:46,217 [+] Orchard.Environment.DefaultOrchardHost-(null)-A tenant could not being started:default
(NULL)
System.UnauthorizedAccessException: Access to Path ' C:\MyWeb\xxx.com\App_Data\Sites\Default\mappings.bin ' is denied.
In System.io.__error.winioerror (Int32 errorCode, String Maybefullpath)
In System.IO.FileStream.Init (String path, FileMode mode, FileAccess access, Int32 rights, Boolean Userights, FileShare Shar E, Int32 buffersize, fileoptions options, Security_attributes secattrs, String Msgpath, Boolean bfromproxy, Boolean Uselon Gpath, Boolean Checkhost)
In System.IO.FileStream. ctor (string path, FileMode mode, FileAccess access, FileShare share, Int32 buffersize, fileoptions options, String Msgpath , Boolean Bfromproxy)
In System.IO.FileStream. ctor (String path, FileMode mode, FileAccess access, FileShare share, Int32 buffersize)
In Orchard.FileSystems.AppData.AppDataFolder.CreateFile (String path)
In Orchard.Data.SessionConfigurationCache.StoreConfiguration (Configurationcache CAC

The Fixe method is to add permissions to the application pool for the current site, as follows:

C:\users\administrator>icacls c:\myweb\xxx.com\app_data/grant "IIS apppool\xxx.com": f/t

Then, everything OK.