What kind of drive is "NoRootDirectory " (System.IO.DriveType.NoRootDirectory)?

Question

In C# System.IO.DriveInfo has the property DriveType.

System.IO.DriveType is an enum:

public enum DriveType
{
    Unknown = 0,
    //
    // Summary:
    //     The drive does not have a root directory.
    NoRootDirectory = 1,
    Removable = 2,
    Fixed = 3,
    Network = 4,
    CDRom = 5,
    Ram = 6,
}

I suspect that this is a volume without a drive letter. But using:

System.IO.DriveInfo.GetDrives();

doesn't list my volume without drive letter.

Is NoRootDirectory used for any other type of volumes / drives or does System.IO.DriveInfo.GetDrives() just not show them?

Answer 1

System.IO.DriveType.NoRootDirectory seems to be an misleadingly designation for "This drive letter is unused"

Testcode for all drives: All not found drives have the type DriveType.NoRootDirectory

foreach (char driveLetter in "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToArray())
{
    var driveInfo = new System.IO.DriveInfo(driveLetter.ToString() + ":\\");

    if(System.IO.DriveInfo.GetDrives().FirstOrDefault(o => o.Name[0] == driveLetter) == null)
        Console.WriteLine("// Not found: " + driveInfo.Name + " has DriveType: " + driveInfo.DriveType.ToString());
    else
        Console.WriteLine("//     found: " + driveInfo.Name + " has DriveType: " + driveInfo.DriveType.ToString());
}

Result:

// Not found: A:\ has DriveType: NoRootDirectory
// Not found: B:\ has DriveType: NoRootDirectory
//     found: C:\ has DriveType: Fixed
//     found: D:\ has DriveType: CDRom
// Not found: E:\ has DriveType: NoRootDirectory
// Not found: F:\ has DriveType: NoRootDirectory
// Not found: G:\ has DriveType: NoRootDirectory
// Not found: H:\ has DriveType: NoRootDirectory
// Not found: I:\ has DriveType: NoRootDirectory
// Not found: J:\ has DriveType: NoRootDirectory
// Not found: K:\ has DriveType: NoRootDirectory
// Not found: L:\ has DriveType: NoRootDirectory
// Not found: M:\ has DriveType: NoRootDirectory
// Not found: N:\ has DriveType: NoRootDirectory
// Not found: O:\ has DriveType: NoRootDirectory
//     found: P:\ has DriveType: Network
// Not found: Q:\ has DriveType: NoRootDirectory
//     found: R:\ has DriveType: Network
//     found: S:\ has DriveType: Network
// Not found: T:\ has DriveType: NoRootDirectory
// Not found: U:\ has DriveType: NoRootDirectory
//     found: V:\ has DriveType: Network
//     found: W:\ has DriveType: Fixed
//     found: X:\ has DriveType: Network
//     found: Y:\ has DriveType: Network
//     found: Z:\ has DriveType: Network