CSNW Drive Mappings Incorrect

• Microsoft Windows NT Server version 3.51

SYMPTOMS

Customers running Client Services for NetWare to access a Novell 3.11 server may intermittently receive incorrect volume information for permanent drive mappings. Visible symptoms of this are File Manager showing the directory information for the wrong volume while the Title Bar in File Manager actually shows the correct volume path (for example, File Manager - VOL1\Home may actually show the SYS\Apps directory).

CAUSE

NetWare clients request directory search handles from a Novell Server for Volumes it would like to reference or map. Novell contains support for Temporary and Permanent directory search handles for volume mapping. Permanent handles are maintained entirely by the client and should only be terminated by the server when a new volume mapping is requested for the same drive letter, or the client connection is terminated. The client maintains the drive mapping by initially requesting a directory search handle, maintaining a reference to it, and requesting that the handle be deallocated when it is done.

Windows NT Client Services for NetWare (CSNW) maintains permanent directory handles in a list of Volume Control Blocks (VCB's) per Server Connection Block (SCB). CSNW frees a permanent directory handle when a VCB (mapping) is freed, or when the owner SCB is marked as down. In the case that the SCB is marked as down, CSNW actually changes the handle to 0xff indicating a new directory search handle needs to be requested for this VCB when the SCB is active again (the connection is re-established) -- like a ghosted connection.

In this case, the Novell server loses track of permanent directory search handles allocated by the Windows NT client. Traces of this problem have shown no deallocation request for a particular permanent directory search handle coming from the Windows NT client, and a debug dump of the VCB list shows a duplicate handle ID is assigned to a new mapping from the Novell server.

RESOLUTION

This problem has been corrected in the latest Service Pack for Windows NT 3.51.

STATUS

Microsoft has confirmed this to be a problem in the interoperation of NetWare and Windows NT version 3.51. A workaround to this problem included in the latest Windows NT 3.51 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K