The Disk Free Space information that is reported in Windows Explorer or in a command window on a Distributed File System (DFS) client for a DFS share is always the Disk Free Space of the drive that contains or hosts the DFS root.
This problem occurs because of a limitation in the server message block (SMB) protocol. The only SMB packet that is available to obtain the Disk Free Space information for a volume is TRANS2_QUERY_FS_INFORMATION together with the subcommand SMB_QUERY_FS_SIZE_INFO. Unfortunately, this command uses the Tree ID from the tree connect to determine which volume to query. If you access a mount point through a share on another volume, the tree connect is to the share. Therefore, the Tree ID refers to the volume that has the share and not to the volume to which the mount points.
The Disk Free Space information that you see in Windows Explorer or that you see by running a command-line command (for example, the DIR command ) on a domain-based DFS client is incorrect. You see disk information about the drive that hosts the SYSVOL share of the domain controller to which you are connected or of the disk that hosts the DFS root folder (that is, the disk that hosts the DFS links). Additionally, "Free space" and "Used Space" information may be displayed incorrectly in Windows Explorer. This problem occurs if you mapped a drive to a share that links to a mounted volume by using NTFS volume mount points or by using symbolic links.
To display the actual free disk space on the destination DFS link folder, follow these steps:
- At a command prompt, type the following command, and then press Enter: DIR \\Domain.company.com\DFSroot\Folder1\Folder2\Folder3
- Notice the bytes free summary line that shows the bytes information.