Merging NDS Trees

The DSMERGE utility allows you to merge the [Root] of two separate NDS trees. Only the [Root] objects are merged; container objects and their leaf objects maintain separate identities within the newly merged [Root].

The two trees you merge are called the source tree and the target tree. To merge two trees, you load DSMERGE on a server in the source tree.

DSMERGE does not change Directory names or contexts within the containers. Object and property rights for the merged objects are retained.

NOTE:  You can't merge container or leaf objects with DSMERGE. To move leaf objects, use NetWare Administrator. To merge partitions, use NDS Manager.

Merging the Source into the Target Tree

When you merge the trees, the servers in the source tree become part of the target tree. (The target tree is the tree that the source tree will be merged into.)

The target [Root] object becomes the new [Root] for objects in the source tree, and the tree name of all servers in the source tree is changed to the target tree name.

After the merge, the target tree name is retained.

The objects that were subordinate to the source [Root] object become subordinate to the target [Root] object.

Partition Changes

During the merge, all replicas of the [Root] partition are removed from servers in the source tree. The server that contained the master replica of the source tree receives a replica of the target tree's [Root] partition.

During the merge, DSMERGE splits the objects below the source [Root] object into separate partitions.

The following two figures illustrate the effect on partitions when you merge two trees.

Figure 2
Directory Trees before a Merge

Figure 3
Directory Tree after a Merge

DSMERGE Options

After you load DSMERGE, you can use the following options:

Preparing the Source and Target Trees

Before performing a merge operation, ensure that the state of synchronization for all servers affected by the operation is stable. The following table provides recommendations for preparing source and target trees for merging.

Because the merge operation is one single transaction, it is not subject to catastrophic failure caused by power outages or hardware failure. However, you should perform a regular backup of the Directory database before using DSMERGE.

Synchronize Time before the Merge

IMPORTANT:  Proper configuration of time synchronization is a very involved process. Make sure you allow enough time to synchronize both trees before you merge the trees.

NDS will not work properly if two external time sources are used, or if all servers in a tree are not synchronized.

Before you do the merge, make sure that all servers in both trees are synchronized, and use only one time source.

There should be a maximum of one reference or one single reference time server in a tree. Likewise, after the merge, the tree should contain only one reference or one single reference time server.

If each of the trees you are merging has either a reference or one single reference time server, you must reassign one of them to refer to the reference or single reference time server in the other tree so that the final tree contains only one reference or single reference time server (if any).

For more information on time synchronization, see Network Time Management.

To view time synchronization information, see Checking Time Synchronization (DSMERGE).

Checking Servers in the Tree

Before you rename or merge trees, use this option to contact all servers in the tree and verify that all servers have the same tree name.

After you rename or merge trees, use this option to verify that all servers have the new tree name.

Prerequisites

• Access to a server console on the source tree or an established RCONSOLE session with the server
• The Supervisor object right to the [Root] object of the source tree

Procedure

1. Load DSMERGE on the server where a replica of the [Root] partition of the source tree is stored.

   At the server console prompt, enter

   LOAD DSMERGE

2. Choose Check Servers in This Tree.

   Each server in the tree is listed in the Status of Servers in the Tree screen, with its corresponding status information. Any servers that have existing problems are flagged and then listed at the top of the server list.

   You should confirm that each server's status is marked as Verified before completing a merge.

   The following table describes the information provided in the Status of Servers in the Tree screen.

   Field	Operation
   Server Name	Lists the names of all servers DSMERGE contacted, and shows their context within the tree.
   Version	Indicates the version of NetWare running on the server.
   Status	UP Indicates that the server is in the right tree. Error number All NDS errors are numbered between -600 and -799 in decimal notation. For information about a specific error code, search the Error Codes information in Troubleshooting or Reference. Unknown Indicates the server is not responding. This is usually because of a downed server or communication problems. Wrong Tree Indicates that this server does not belong to this Directory tree. This status might occur if the tree was recently merged or renamed because the server might take a few minutes to recognize the change. Or, this status can occur if the server was reinstalled in another tree, but not properly removed from this tree. If so, delete this server's object from this tree.

Checking Time Synchronization (DSMERGE)

Use this procedure on both trees before merging them.

Prerequisites

• Access to a server console on both the source and target trees or an established RCONSOLE session with the servers
• The Supervisor object right to the [Root] object of both the source and target trees

Procedure

1. Load DSMERGE on the server that contains a master replica of the [Root] partition of the source tree.

   At the server console prompt, enter

   LOAD DSMERGE

   If you don't know where the master replica is, load DSMERGE on any server in the source tree. You will be prompted with the name of the server that contains the master replica when it is required.

2. Choose Check Time Synchronization.

   The Time Synchronization Information for Tree treename screen appears.

   This option displays a list of all servers in the tree, along with information about their time sources and the server time.

   Verify that all servers in the tree are synchronized and that they are using the same time source.

   The following table describes the information provided in the Time Synchronization Information for Tree treename screen.

   Field	Operation
   Server Name	Lists the name of each server recorded in the tree's [Root] partition. If the server could not be contacted, it is listed as Unknown.
   Type	Indicates the kind of time server the server is using.
   In Sync	YES Indicates that the server is in sync with the time server. NO Indicates that the server is not in sync with the time server. This option does not indicate if the source server is in sync with the server you have selected. Check the type of time server each server is using to determine if they are using different time servers.
   Time Delta	Displays the difference in time between the source server and the selected server in the list. If the difference in time is more than a few minutes, it might indicate that the servers are using different time servers.

Merging Two Trees

For complete functionality of all menu options in DSMERGE, load DSMERGE on a server that contains the master replica.

If you don't know where the master replica is stored, you will be prompted with the correct server name when you attempt an operation that requires the master replica.

To perform a merge operation, you must load DSMERGE on the source tree.

When merging large trees, it's significantly faster to designate the source tree as the tree with fewer objects immediately subordinate to the [Root]. By doing this, you create fewer partition splits during the merge, since all target tree objects result in new partitions.

IMPORTANT:  Because the source tree name no longer exists after the merge, you may need to change your client workstation configurations. For Novell Client for DOS and Windows, check the Preferred Tree and Preferred Server statements in the net.cfg files. For Novell Client for Windows NT and Novell Client for Windows 95 check the Preferred Tree and Preferred Server statements on the client Property Page.

To minimize the number of client workstations you need to update, designate the tree with the most client workstations as the target tree, because the final tree retains the name of the target tree.

Or, rename the tree after the merge operation so that the final tree name corresponds to the tree with the greater number of client workstations attaching to it. See Renaming the Tree.

Prerequisites

• Access to the server console on the source tree or an established RCONSOLE session with that server
• The Supervisor object right to the [Root] object of both trees you want to merge
• A backup of the NDS database for the two trees
• All servers in both trees are synchronized and using the same time source
• (Optional) All servers in the tree are operational. (Servers that are down will update automatically when they are operational.

Procedure

1. Load DSMERGE on the server where the master replica on the source tree is stored.

   At the server console prompt, enter

   LOAD DSMERGE

   If you don't know where the master replica is stored, you will be prompted with the correct server name when you attempt to merge the trees.

2. Choose Merge Two Trees.

   The Merge Tree Information screen appears.

3. Enter the administrator name and password to log in to the source tree.

   Log in as a user who has the Supervisor object right to the [Root] object on the source tree. Enter the typeless or typeful distinguished name, such as admin.novell or cn=admin.o=novell. Entering only admin is invalid because it is not the complete name of the User object.

4. Choose Target Tree and select a target tree from the list of servers in the Available Trees window.

   If the tree you want is not in the list, press Insert and enter the target tree's network address.

5. Enter the administrator name and password to log in to the target tree.

6. Press F10 to perform the merge.

   A message stating that the trees have been merged successfully is displayed.

Renaming the Tree

You must rename a tree if the two trees you want to merge have the same name.

You can rename only the source tree name. To rename the target tree, run DSMERGE from a server on the target tree.

After you change a tree's name, you may need to change your client workstation configurations. For Novell Client for DOS and Windows, check the Preferred Tree and Preferred Server statements in the net.cfg files. For Novell Client for Windows NT and Novell Client for Windows 95, check the Preferred Tree and Preferred Server statements on the client Property Page.

When you merge two trees, to minimize the number of client workstations that need to be updated, designate the tree with the most client workstations as the target tree because the final tree retains the name of the target tree.

Or, rename the tree after the merge so that the final tree name corresponds to the tree name with the majority of client workstations.

Another option is to rename the merged tree to the name of the original source tree. If you choose this option, then you must update the net.cfg files on the target tree client workstations.

Prerequisites

• Access to a server console on the source tree or an established RCONSOLE session with the server
• The Supervisor object right to the [Root] object of the source tree
• (Optional) All servers in the tree are operational. (Servers that are down will update automatically when they are operational.)

Procedure

1. Load DSMERGE on the server where a master replica of the [Root] partition is stored.

   At the server console prompt, enter

   LOAD DSMERGE

   If you don't know where the master replica is, load DSMERGE on any server in the source tree. Then you will be prompted with the correct server name when you attempt to rename a tree.

2. Choose Rename This Tree.

3. Enter the administrator name and password to log in to the source tree.

   Log in as a user who has the Supervisor object right to the [Root] object on the source tree. Enter your complete name, such as admin.novell or cn=admin.o=novell. Entering only admin is invalid since it is not a complete name.

4. Enter the new tree name.

5. Press F10 to perform the rename.

Completing the Tree Merge

Following the merging of two trees, it might be necessary to complete the following tasks:

1. (Optional) Choose Checking Servers in the Tree in the DSMERGE main menu to confirm that all tree names were changed correctly. See Checking Servers in the Tree.
2. Check the new partitions that the merge operation created. If you have many small partitions in the new tree, or if you have partitions that contain related information, you might want to merge them. See NDS Database Management.
3. Copy a new replica to any non-NetWare 5 servers after the merge is complete, if you did not upgrade before running DSMERGE.
4. Recreate any leaf objects or aliases at the [Root] that were deleted before you ran DSMERGE.
5. Evaluate partitioning of the NDS tree.

   Merging trees might significantly change replica placement on the source tree. You should carefully evaluate and change the partitioning as needed.

6. Update your client workstation configuration. For Novell Client for DOS and Windows, check the Preferred Tree and Preferred Server statements in the net.cfg files. For Novell Client for Windows NT and and Novell Client for Windows 95, check the Preferred Tree and Preferred Server statements on the client Property Page. Or rename the target tree.

   Only the target tree name is retained after the merge.

   HINT:  To minimize the number of net.cfg files you need to update, designate the tree with the most client workstations as the target tree because the final tree retains the name of the target tree.

   Or rename the tree after the merge operation so that the final tree name corresponds to the majority of the client workstations' net.cfg files. See Renaming the Tree.

The target [Root] object becomes the new [Root] for servers moved from the source tree. The Access Control List (ACL) for the [Root] object of the source tree is preserved. Therefore, the rights of the source tree's user admin to the [Root] object are still valid.

After the merge is complete, both admin users still exist and are uniquely identified by different container objects.

IMPORTANT:  For security reasons, you might want to delete one of the two admin User objects or restrict the rights of the two objects.