DosDevices

DosDevices
there is one global \DosDevices directory and multiple local \DosDevices directories.The global \DosDevices directory holds the MS-DOS device names that are visible system-wide.A local \DosDevices directory holds MS-DOS device names that are visible only in a particular local DosDevices context(see below to understand local DosDevices context).

each logon session has its own local DosDevices context,If a user mounts a network drive as X:, only himself can see this。

Each thread has a current DosDevices context, which can change over the lifetime of a thread.

when the object manager looks up a name in \DosDevices, it first searches the local \DosDevices directory, and then the global \DosDevices directory.

A driver that must create its MS-DOS device names in the global \DosDevices directory can do so by creating its symbolic links in a standard driver routine that is guaranteed to run in a system thread context, such as DriverEntry{RtlInitUnicodeString(&symbolicLinkName, L"\\DosDevices\\Global\\SymbolicLinkName");}.
When a thread in a particular local DosDevices context sends an IOCTL, the driver's DispatchDeviceControl is called from within the current thread context. A driver can create MS-DOS device names in a local \DosDevices directories by creating the symbolic link in response to the IOCTL.

On Windows XP and later, local \DosDevices directories are identified by the AuthenticationID for the logon session's access token.