There are many scenarios where you will want Universal
Naming Convention (UNC) paths to remain unchanged when the underlying files are
moved to other servers or to other paths. For example, you may want to preserve
the UNC paths that users are accustomed to if you migrate or consolidate your
existing file servers to new Microsoft Windows Server 2003-based computers. The
paths may be embedded in links, in line-of-business applications, and in other
places where the names are difficult to change. This article describes a
software update that provides the functionality to keep UNC paths the same when
you move the path's underlying files. The software update modifies the
Microsoft Distributed File System (DFS) server to permit the DFS server to
return referrals for servers that no longer exist. The DFS server that permits
this functionality is referred to as the DFS root server.
Note A clustered environment supports a DFS root server, where the DFS
shares will move among cluster members.
A supported feature that modifies the default behavior of the
product is available from Microsoft. However, this feature is intended to
modify only the behavior that this article describes. Apply this feature only
to systems that specifically require it. This feature might receive additional
testing. Therefore, if the system is not severely affected by the lack of this
feature, we recommend that you wait for the next software update that contains
this feature.
If the feature is available for download, there is a
"Hotfix download available" section at the top of this Knowledge Base article.
If this section does not appear, contact Microsoft Customer Service and Support
to obtain the feature.
Note If additional issues occur or if any troubleshooting is required,
you might have to create a separate service request. The usual support costs
will apply to additional support questions and issues that do not qualify for
this specific feature. For a complete list of Microsoft Customer Service and
Support telephone numbers or to create a separate service request, visit the
following Microsoft Web site:
Note The "Hotfix download available" form displays the languages for
which the feature is available. If you do not see your language, it is because
the feature is not available for that language.
You must restart the Distributed File System service after you
apply this software update. You must restart the Server service (Lanmanserver)
after you configure the registry values that are discussed in the "More
Information" section.
The English version of this software update has the file
attributes (or later file attributes) that are listed in the following table.
The dates and times for these files are listed in Coordinated Universal Time
(UTC). When you view the file information, it is converted to local time. To
find the difference between UTC and local time, use the Time
Zone tab in the Date and Time item in Control
Panel.
Date Time Version Size File name Platform
----------------------------------------------------------------------
26-Jan-2004 20:06 5.2.3790.124 32,768 Dfs.sys x86
30-Jan-2004 19:04 5.2.3790.124 136,704 Dfssvc.exe x86
17-Jan-2004 11:54 5.2.3790.121 97,792 Dfs.sys IA-64
17-Jan-2004 11:54 5.2.3790.121 458,752 Dfssvc.exe IA-64
Important Clients with persistent drive mappings will not reconnect after
the clients use this update to consolidate servers. Any persistent drive
mappings on client computers must be deleted and recreated. Restarting is not
sufficient. This issue only affects persistent drive mappings. Drives that are
mapped through logon scripts at each log on work correctly.
This
section describes procedures to:
Install the software update.
Configure your DFS root server to support the consolidation
of the UNC paths from the old servers.
In the following examples, the name root1.contoso.com
represents the DFS root server, and the names oldserver1.contoso.com,
oldserver2.contoso.com, and oldserver3.contoso.com represent the old servers
that you want to consolidate.
Before you set up your DFS root server,
make sure that you understand the following concepts:
For the DFS root server to redirect paths for multiple
servers, Windows Server 2003, Enterprise Edition or Windows Server 2003,
Datacenter Edition is required.
If you set up your DFS root server on a Windows Server 2003
domain controller, you will disable the server consolidation logic.
The DFS root server scenario is only supported if the
NetBIOS name of the DFS root server is the same as the host name part of its
fully qualified domain name (FQDN).
The consolidation of UNC paths from two servers that have
the same host name is not supported. For example, you cannot consolidate two
servers that are named oldserver1.contoso.com and
oldserver1.subdomain.contoso.com.
How to configure a DFS root server for consolidation in a non-clustered server environment
Set up a Windows Server 2003 DFS root server that will act
as the consolidation server for the old namespaces. On the DFS root server,
follow these steps:
Install the software update that is described in this
article to enable the new DFS consolidation functionality.
After you install the software update, restart the DFS
service.
On the DFS root server, click Start, click
Run, type regedit in the
Open box, and then click
OK.
Important This section, method, or task contains steps that tell you how to
modify the registry. However, serious problems might occur if you modify the
registry incorrectly. Therefore, make sure that you follow these steps
carefully. For added protection, back up the registry before you modify it.
Then, you can restore the registry if a problem occurs. For more information
about how to back up and restore the registry, click the following article
number to view the article in the Microsoft Knowledge Base:
322756
(http://support.microsoft.com/kb/322756/
)
How to back up and restore the registry in Windows
Create and configure the ServerConsolidationRetry registry
entry, as follows:
Locate and then click the following registry subkey:
On the Edit menu, point to
New, and then click DWORD Value.
Type LogServerConsolidation, and
then press ENTER.
In the Value data box, type
1, and then click OK.
This will log the logical path and the client computer’s IP
address to the system event log as event ID: 14318. Make sure to allocate
sufficient space to the system event log. Microsoft recommends that you set the
system event log to at least 64 megabytes. Make sure to set the system event
log to overwrite events as needed.
Note Currently, the user’s name and the computer name are not logged
in the system event log.
In the DFS snap-in, create a DFS root for each old server
that you want to redirect. Make sure that you include a hash mark (#) at the
start of the old server name.
Note If the old server is a domain controller, demote the domain
controller before you move the name to the DFS root server.
Click Start, point to All
Programs, point to Administrative Tools, and then
click Distributed File System.
On the Action menu, click New
Root, and then click Next.
Click Stand-alone root, and then
click Next.
Click Browse, click the name of the
DFS root server, click OK, and then click
Next.
In the Root name box, type the host
name of the old server with a hash mark in front of it, and then click
Next. For example, type
#oldserver1.
In the Folder to share box, type the
name of the folder to share or locate an existing folder share.
The
local path for the share can point to a local empty folder. For example, the
root names in the sample scenario would be \\root1\#oldserver1 and
\\root1\#oldserver2.
Note The hash mark informs the DFS root server that this DFS root is
used for server consolidation. When you access a file on the path, you do not
have to specify a hash mark. For example, use the path
\\oldserver1\public\test.doc, not the path
\\#oldserver1\public\test.doc.
In the DFS snap-in, for each share on each old server,
create a link under the root for each share that will be redirected. The target
path must be the new location of the share, either on another server or in a
domain-based DFS namespace.
In the DFS snap-in, right-click the old server root,
and then click New Link.
In the Link name box, type a name for
the link.
In the Path to target (shared folder)
box, click Browse, click the new location of the share, and
then click OK.
To link each share on the old server to the new share
location, repeat steps a through c.
Note DFS root servers that are enabled for consolidation are not
supported as the targets of a DFS link. DFS links that point to the old servers
must be rewritten to point to the target of the consolidated root. Consider the
following scenario: \\oldserver1\public is consolidated to \\root1 such that
\\root1\#oldserver1 points to a DFS root server (\\consolidated\public) that is
enabled for consolidation. In this scenario, DFS links with \\oldserver1\public
as a target are not supported. To bypass the DFS root server that is enabled
for consolidation, you must rewrite these links to point to
\\consolidated\public. Link names with "\" characters, such as a link of the
form “a\b”, are not
supported on DFS root servers that are enabled for consolidation.
If you use a Microsoft Windows 2000 server, follow these
steps to make sure that the Automatically update DHCP client
information in DNS check box is selected only at the server level.
Make sure that this check box is not selected at the DHCP scope level.
Note If you use a Windows Server 2003 DHCP server, make sure that the
Enable DNS dynamic updates according to the settings below
check box is selected only at the server level. Make sure that this
check box is not selected at the DHCP scope level.
On the DHCP server, click Start, point
to Programs, point to Administrative Tools,
and then click DHCP.
Expand your DHCP server name, right-click
Scope, and then click Properties. In this
case, right-click the first scope in the list.
Click the DNS tab.
Click to clear the Automatically update DHCP
client information in DNS check box.
Note If you use a Windows Server 2003 DHCP server, click to clear the
Enable DNS dynamic updates according to the settings below
check box.
Repeat steps b through d for each DHCP
scope.
Move your data from the old file server location to the new
location.
On the Windows Internet Name Service (WINS) server, verify
that static WINS entries do not exist for the old servers. If they do, delete
the static entries. For more information about how to delete static WINS
entries, visit the following Microsoft Web site:
Note To find the information about how to delete static WINS entries,
locate Troubleshooting WINS Servers on the Web site,
click The server cannot resolve names for clients, and then
click To delete or tombstone an entry in the WINS
database.
Modify the Domain Name System (DNS) records so that the old
server names will resolve to the DFS root server.
For Active Directory environments that use Windows 2000
or later DNS and DHCP servers, follow these steps on the DFS root server:
On the Edit menu, point to
New, and then click Multi-String
Value.
Type AlternateComputerNames,
and then press ENTER.
On the Edit menu, click
Modify.
In the Value data box, type the
fully qualified DNS names of the old servers. This action registers the names
in DNS. Each server name must be on its own line. For example, type:
For non-Active Directory environments or for
environments that do not use Windows DNS servers, modify the "A" records for
old server names. (For example, modify the names for oldserver1.contoso.com,
oldserver2.contoso.com, and oldserver3.contoso.com.) in DNS to point to the DFS
consolidation server (root1.contoso.com).
From a command prompt on the DFS root server, type the
following command:
ipconfig /registerdns
On the DFS root server, follow these steps to configure
the OptionalNames registry value:
Locate and then click the following registry subkey:
On the Edit menu, point to
New, and then click Multi-String Value.
Type OptionalNames, and then
press ENTER.
On the Edit menu, click
Modify.
In the Value data box, type the
NetBIOS names of the old servers (oldserver1, oldserver2, and oldserver3) each
on their own line, and then click OK. This action registers
the names in Windows Internet Name Service (WINS) for the DFS root server.
Restart the Server service on the DFS root
server.
How to configure a DFS root server for consolidation in a clustered server environment
On each server in the cluster, set up a Windows Server 2003
DFS root server that will act as the consolidation server for the old
namespaces. On both cluster nodes, follow these steps:
Install the software update that is described in this
article to enable the new DFS consolidation functionality.
After you install the software update, restart the
Distributed File System service.
On the node that will be used for the online DFS root,
click Start, click Run, type
regedit in the Open box, and then click
OK.
Important This section, method, or task contains steps that tell you how to
modify the registry. However, serious problems might occur if you modify the
registry incorrectly. Therefore, make sure that you follow these steps
carefully. For added protection, back up the registry before you modify it.
Then, you can restore the registry if a problem occurs. For more information
about how to back up and restore the registry, click the following article
number to view the article in the Microsoft Knowledge Base:
322756
(http://support.microsoft.com/kb/322756/
)
How to back up and restore the registry in Windows
On the node that will be used for the online DFS root,
create and configure the ServerConsolidationRetry registry value, as follows:
Locate and then click the following registry subkey:
On the Edit menu, point to
New, and then click DWORD Value.
Type ServerConsolidationRetry,
and then press ENTER.
On the Edit menu, click
Modify.
In the Value data box, type
1, and then click OK.
To log a system event every time that the DFS root server
successfully resolves a referral, follow these steps on the node that will be
used for the online DFS root:
Locate and then click the following registry subkey:
On the Edit menu, point to
New, and then click DWORD Value.
Type LogServerConsolidation, and
then press ENTER.
In the Value data box, type
1, and then click OK.
This will log the logical path and the client computer’s IP
address to the system event log as event ID: 14318. Make sure to allocate
sufficient space to the system event log. Microsoft recommends that you set the
system event log to at least 64 megabytes. Additionally, set the system event
log to overwrite events as needed.
Note Currently, the user’s name and the computer name are not logged
in the system event log.
Use the Cluster Administrator or the cluster utility
(Cluster.exe) to add the following registry subkey to the list of replicated
registry keys:
When you add this registry subkey to the list of replicated
registry keys, the Cluster service will copy the registry values over to the
failover node if the hard disk on the online cluster node fails over to another
node.
Use
the following cluster command to create a checkpoint:
Cluster.exe /cluster:<cluster_name> res <resource_name> /addcheckpoints:SYSTEM\CurrentControlSet\Services\Dfs\Parameters\Replicated
For more information about how to manage
a server cluster from the command line, visit the following Microsoft Web site:
On the Windows Internet Name Service (WINS) server, verify
that static WINS entries do not exist for the old servers. If they exist,
delete the static entries. For more information about how to delete static WINS
entries, visit the following Microsoft Web site:
Note To find the information about how to delete static WINS entries,
locate Troubleshooting WINS Servers on the Web site,
click The server cannot resolve names for clients, and then
click To delete or tombstone an entry in the WINS
database.
Move your data from the old file server location to the new
location.
From the cluster utility, create a name resource for each
old server that you want to consolidate.
From the cluster utility, create a file share resource with
the IsDFS flag set.
NoteTo
confirm that the IsDFS flag is enabled, IsDFS will show as "IsDFSRoot" if it is
running "cluster.exe res <resource_name> /priv." If the value is 0x1, it
is set correctly.
From the cluster utility, bring the resources
online.
In the DFS snap-in on one of the cluster nodes, follow
these steps to create a DFS root for each old server that you want to redirect.
Make sure that you include a hash mark (#) at the start of the old server
name.
Note If the old server is a domain controller, demote the domain
controller before you move the name to the DFS root server.
Click Start, point to All
Programs, point to Administrative Tools, and then
click Distributed File System.
On the Action menu, click New
Root, and then click Next.
Click Stand-alone root, and then
click Next.
Click Browse, click the name of the
DFS root server, click OK, and then click
Next.
In the Root name box, type the host
name of the old server with a hash mark in front of it, and then click
Next. (For example, type
#oldserver1.)
In the Folder to share box, type the
name of folder to share or locate an existing folder share.
The local
path for the share can point to a local empty folder. For example, the root
names in the sample scenario would be \\root1\#oldserver1 and
\\root1\#oldserver2.
Note The hash mark informs the DFS root server that this DFS root is
used for server consolidation. When you access a file on the path, you do not
have to specify a hash mark. For example, use the path
\\oldserver1\public\test.doc, not the path
\\#oldserver1\public\test.doc.
In the DFS snap-in, for each share on each old server,
follow these steps to create a link under the root for each share that will be
redirected. The target path must be the new location of the share, either on
another server or in a domain-based DFS namespace.
In the DFS snap-in, right-click the old server root,
and then click New Link.
In the Link name box, type a name for
the link.
In the Path to target (shared folder)
box, click Browse, click the new location of the share, and
then click OK.
For each share on the old server to link to the new
share location, repeat steps a through c.
Note DFS roots servers that are enabled for consolidation are not
supported as the targets of a DFS link. DFS links that point to the old servers
must be rewritten to point to the target of the consolidated root. Consider the
following scenario: \\oldserver1\public is consolidated to \\root1 such that
\\root1\#oldserver1 points to a DFS root server (\\consolidated\public) that is
enabled for consolidation. In this scenario, DFS links with \\oldserver1\public
as a target are not supported. You must rewrite such links to point to
\\consolidated\public to bypass the DFS root server that is enabled for
consolidation. Link names with "\" characters, such as a link of the form
“a\b”, are not supported
on DFS root servers that are enabled for consolidation.
If you use a Windows 2000 DHCP server, following these
steps to make sure that the Automatically update DHCP client
information in DNS check box is selected only at the server level.
Make sure that this check box is not selected at the DHCP scope level.
Note If you use a Windows Server 2003 DHCP server, make sure that the
Enable DNS dynamic updates according to the settings below
check box is only selected at the server level. Make sure that this check box
is not selected at the DHCP scope level.
On the DHCP server, click Start, point
to Programs, point to Administrative Tools,
and then click DHCP.
Expand your DHCP server name, right-click
Scope, and then click Properties. In this
case, right-click the first scope in the list.
Click the DNS tab.
Click to clear the Automatically update DHCP
client information in DNS check box.
Note If you use a Windows Server 2003 DHCP server, click to clear the
Enable DNS dynamic updates according to the settings below
check box.
Description of the DFS root server consolidation logic
After you complete the steps for DFS root server consolidation,
and you try to open a file at the old share path, the following scenario
occurs:
The DFS root server sees the request and reads the
ServerConsolidationRetry registry entry.
The DFS root server adds its server name, together with a
hash mark (#) at the beginning of the name, to the lookup path. For
example, if you try to open a file at the old share path of
\\oldserver1\public\test.doc, the DFS root server looks up
\\root1\#oldserver1\public\test.doc.
The DFS root server returns a referral to the link target
to the client. If the lookup fails, the DFS server looks up the original path
specified by the user.
The server consolidation logic is as follows:
If an incoming lookup request has the local computer name
specified for the server, go to step 5.
Look up the server name in the share path by using the
NetBIOS or FQDN server name that is specified by the user. For example, if a
user specifies \\oldserver1.contoso.com\public\test.doc, search for
\\root1\#oldserver1.contoso.com\public\test.doc.
If the user specifies the FQDN name, and step 2 fails,
truncate the server name at the first ‘.’ and treat the value as the NetBIOS
server name. Use the NetBIOS server name in the path to look up the referral.
For example, if a user specifies \\oldserver1.contoso.com\public\test.doc, then
search for \\root1\#oldserver1\public\test.doc.
If either step 2 or step 3 successfully resolves the server
name, try to match the whole lookup path. If the whole lookup path matches,
return the successful referral to the client, and then skip step 5.
If only a part of the path can be matched, fail the lookup and return
an error to the user. For example, if the user specifies
\\oldserver1\public\test.doc and only \\root1\#oldserver1 is matched, the
search is unsuccessful and the lookup fails. Skip step 5.
Search for the path that was specified in the original
referral. For example, if the original request is for \\root1\public\test.doc,
search for public\test.doc.
For more information about the standard
terminology that Microsoft uses when it corrects software after it is released,
click the following article number to view the article in the Microsoft
Knowledge Base:
824684
(http://support.microsoft.com/kb/824684/
)
Description of the standard terminology that is used to describe
Microsoft software updates
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