
Mounted folders disappear in shared folders
If you have either a Mounted Volume or Junction Point that maps to the root of a volume you may find that this folder intermittently disappears when accessed through a shared folder.
A Mounted Volume is a volume mounted in an NTFS folder typically created using the Disk Management MMC console
A Directory Junction point is a folder referral that is typically created using
MKLINK.exe /J
The problem is caused by the SMBv2 Client Redirector Cache and has been acknowledged by Microsoft as a known problem in the following operating systems:
- Windows 7
- Windows Server 2008
- Windows Server 2008 R2
The problem can easily be observed by performing the following actions:
Note, all actions assume you are using one of the above operating systems in all cases
- Access a remote file server share that has a mounted volume folder within it
- Access the mounted volume folder
- Go back to a folder above the mounted volume, or access the remote file server share again
- The mounted volume folder should now be hidden
- The mounted volume folder is still accessible using the full path
Workaround
The following workarounds can be used to remove the problem:
- Set the following registry key to disable caching
Setting this registry key removes some of the performance improvements in SMBv2 and can potentially increase load on the file servers
Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters DWORD Name: DirectoryCacheLifetime Value: 0 - Change the volume mount point or junction point to map to a directory within the volume instead
- Disable SMBv2 which disables the caching feature introduced in SMBv2
Not Recommended.
Microsoft have released a knowledge base article to address this specific problem:
https://support.microsoft.com/en-us/kb/2461645