What is the "~DFSINFO.8-P" file on the root of volumes used for?

(Last modified: 15Sep2003)

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goal

fact

Novell NetWare 6.0

Network Storage Services (NSS)

NSS

fix

The DFS GUID for a volume is stored in the Volume's NDS object, but NetWare also stores it in the ~DFSINFO.8-P file on the root of the volume itself in case the NDS object gets trashed, or to handle the case where a volume doesn't have an NDS object. Additional information may also be maintained in this file in future releases.

VLDB is the Volume Location Database, used by DFS (Distributed File Services). DFS assigns a GUID to each volume in the network, and the VLDB keeps track of the physical locations of the volumes. A junction (which just looks like a subdirectory to the end user, but is actually a pointer to the root of another volume) contains the GUID of the target volume, and so when a client (or service acting on behalf of the client, as happens with CIFS) sees a junction, it reads the GUID out of the junction file and looks it up in the VLDB to find out where the volume actually is. NetWare maintains the location information in the VLDB so that it is easy to change if the volume moves to another server (a feature being investigated for future releases of NetWare). By having this level of indirection, NetWare only has to update the target information in one place (the VLDB) rather than searching for and updating all the junctions in the entire management domain that point to the volume.

A logical question is why doesn't NetWare just put the volume location information into NDS. NDS propagates changes rather slowly compared to the near-instantaneous updates required for file system and volume relocation activities. Note that one way to move a volume from one server to another is to back it up on the first server, then delete it and restore it on another server. By having the file that stores the volume's DFS GUID part of the backed-up data, the newly created instance of the volume automatically has the correct (same) GUID as the original instance, so now a repair of the VLDB can be run and it will pick up the new location for the volume automatically.

It "~DFSINFO.8-P" is supposed to be hidden, but may still be visible to administrators or other scenarios where hidden files are being displayed.

By design the "~DFSINFO.8-P" file should be included in file system backups. One of the intentions in leaving the file as a regular file system file is so it would be backed up and restored as part of a normal volume backup operations.

For additional information on NetWare 6, please see the following solution. TID #10064501 - NetWare 6 Readme Addendum

document

Document Title:	What is the "~DFSINFO.8-P" file on the root of volumes used for?
Document ID:	10066461
Solution ID:	NOVL64956
Creation Date:	30Nov2001
Modified Date:	15Sep2003
Novell Product Class:	NetWare

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