SERVER MAINTENANCE: Maintaining NDS Information for a NetWare 4.11 Server During a Brief Shutdown or Hardware Upgrade
Articles and Tips: article
01 Oct 1996
Provides steps for using new options in the NetWare 4.11 INSTALL utility to keep NDS information intact when you perform server maintenance.
The NetWare 4.11 INSTALL.NLM utility includes several new options to help you preserve Novell Directory Services (NDS) information when you need to bring down a server for maintenance operations. The new options are found by selecting "Directory options (install NetWare Directory Services)" from INSTALL's main menu and then selecting "Directory backup and restore options" (see Figure 1).
Figure 1: Directory backup and restore options in INSTALL.NLM.
These options offer the same functionality that DSMAINT.NLM provides for NetWare 4.1 servers. These enhancements to the INSTALL utility address two cases of planned server outages: shutting down a server temporarily, and upgrading server hardware.
Maintaining Server Object References During a Brief Shutdown
At times, it is necessary to remove a NetWare Server object from the NDS tree for a brief period of time. For example, if an authentication key is corrupted, it is necessary to reinstall NDS on the server. During the uninstall process, the Server object is removed from the tree and other objects that reference the Server object in their required attributes can become Unknown objects. A similar type of problem can occur with services such as printing that are associated with a physical server. If the server referenced in a Queue object's Host Server attribute is removed, the Queue remains a known object but it is useless because it has lost the link to the queue directory on the server.
With the enhanced INSTALL, you can avoid losing objects and ease reinstallation by substituting references to the server with references to another object that you create for this purpose. After reinstalling NDS on the server, you can use INSTALL to replace these references to the server in other objects' Host Server, Host Device, or Message (Default) Server attributes.
Here are the steps for performing this procedure:
Note: You must have at least two servers on your network inorder for this procedure to work.
Load INSTALL.NLM on the server you are going to shut down. Select "Directory options" and then "Remove Directory Services from this server." When prompted, enter the Admin username and password.
INSTALL displays the prompt "Enter the placeholder object distinguished name" with the name of the current server listed as a default. This is where you select another object for "holding" the server references. The object you use must not be a NetWare Server object, but it can be an existing User object. The user object you have logged in as would be an appropriate choice. Enter the object's full distinguished name; for example, .CN=Admin.O=ABC.
The next prompt is "Change from which distinguished name and below" with the default of [Root] displayed. This is where you enter the full distinguished name of the container where you want to begin searching for objects that reference this server's NetWare Server object. In most cases, you should leave this option set to [Root].
If this server holds a master replica, INSTALL will prompt you to select an option to switch the master replica to another server in the replica ring.
At this point, you can continue the process of removing Novell Directory Services and bringing down the server.
Once you have completed the required maintenance operation on the server, reload INSTALL and select "Directory options", followed by "Directory backup and restore options." Select the "Restore references from another object to this server" option to reverse the substitutions made previously in Steps 2 and 3. You will again be required to provide the full name of the temporary object that is holding the references.
Note: INSTALL automatically removes volume IDs from thephysical volumes on the server so that Volume objectsare not removed during an uninstall.
Upgrading Server Hardware
There are times when a server requires an upgrade that does not affect the server as an NDS object. For example, the SYS volume may be physically located on an old hard disk drive that needs to be upgraded. In these situations, you no longer need to uninstall NDS from the server. You can use INSTALL to save NDS information in preparation for the planned hardware upgrade of the server. After the upgrade, you can restore this NDS information to the server with INSTALL.
Before you run INSTALL, you should have a current, full file system backup of your server.
The "Save local DS information prior to hardware upgrade" option prepares the NDS information on this server prior to the upgrade. When you select this option, INSTALL creates a file called BACKUP.NDS in the server's SYS:SYSTEM directory. This file stores all the NDS information for this server, including replica information. You will be prompted to save this file to another server on your network.
Using this option locks and disables the NDS database on this server, preventing any data changes from taking place. To other servers that normally communicate with this server, the server appears to be down. Any NDS information that normally is sent to the locked server is held by other servers in the tree; when the server comes back online, this "stored" information is used to resynchronize the server.
Because other servers in the tree are expecting the server to come back online quickly, you should not plan to take several days to upgrade the server. Complete the upgrade promptly and restore NDS information on the server as soon as possible.
The "Restore local DS information after hardware upgrade" option uses the BACKUP.NDS file created by the "Save local DS information..." option to restore NDS information on this server. Before the NDS information is restored, INSTALL verifies that the server is in the same relative state as before the upgrade. INSTALL verifies that the server's object and authentication keys still exist and that the server still exists in all the replica rings for copies that were on this server before the upgrade.
It is important that NDS partition and replica information remain consistent during the entire upgrade process. No replicas should be added or removed, nor should any replica/partition types be changed during this time. Likewise, no existing servers should be uninstalled and reinstalled, nor should any new servers be installed until the Save and Restore procedure is complete. If consistency of the tree (including partitions, replicas and placement of replicas, and servers) is not maintained, the INSTALL verification process will return a -601error during the Restore phase and the process cannot be completed.
As always, be aware of the dependencies that other servers currently have on the server you are upgrading. Take into consideration processes such as NDS time synchronization. If the server plays a crucial part in the time synchronization of the NDS tree (for example, if it is a Reference time provider), you need to reassign the time server functions and responsibilities to another server before you run INSTALL. Check to make sure the tree has valid time synchronization status before continuing. (See TID 2908156 "Time Synchronization Issues and Definitions" and TID 2911661 "Changing Time Source Type" for additional information. Both documents are available on the World Wide Web at http://support.novell.com.)
Before starting the procedure, use NDS Manager to verify the integrity of the tree and the synchronization status of the partitions/replicas that the candidate server contains. Resolve any errors before continuing. (See the NetWare 4.11 document-ation for instructions.)
Note: For this procedure, you need at least two NetWareservers in your NDS tree and replicas of all partitionscontained on the candidate server.
Here are the steps for performing this procedure:
If you already have a current backup, log in from a client workstation as Admin. Skip to Step 3.
If you don't have a current backup, use an SMS-compatible backup program to do a file system backup of the server's volume(s). For additional information on backup and restore, refer to "Backing Up and Restoring NDS in NetWare 4.11" in this issue of AppNotes.
Load INSTALL and choose "Directory options" from the main menu, then select "Directory backup and restore options".
Select the "Save local DS information prior to hardware upgrade" option and authenticate as prompted. The BACKUP.NDS file is created in the server's SYS:SYSTEM directory.
When prompted to copy the file, choose the path. The default is A: for copying to a diskette. Press <F3< to specify a different path. Type the second server's name and path, and authenticate to the remote server as prompted.
Exit the INSTALL utility.
Bring down the server and perform the hardware upgrade.
Start up the INSTALL utility again. When prompted to select an NDS tree, don't. Press <F5< instead, and then press <F3<.
Choose the "Restore local DS information after hardware upgrade" option. When prompted for the file path, press<F3< and enter the path to the BACKUP.NDS file on the second server. Re-authenticate as prompted. The correct NDS information will be restored to the server.
Load TSA410.NLM on the server and start your backup program. From the backup performed in Step 2, restore data to any volumes that were affected by the hardware upgrade.
-- Michael Fairbanks, Ken Neff
Permanently Removing a Functional Server from an NDS Tree
Customers frequently ask about the proper way toremove a NetWare 4 server from the network. It isimportant to remember that NetWare 4 is a distributednetwork environment in which servers are constantlycommunicating with each other. If you need to permanently remove a functioning NetWare 4 serverfrom an NDS tree, it must be done properly usingINSTALL.NLM. Do not just disconnect the server from thenetwork! If a server is removed incorrectly, it couldcause NDS synchronization problems.
Here are the steps:
Load the Install utility by typing LOAD INSTALL.
From the Installation Options menu, select "Directory Options (install NetWare Directory Services)."
From the Directory Services Options menu, select "Remove Directory Services from this server." Answer "Yes" to the confirmation prompt, and typethe password for an administrative user when prompted.
Respond to the on-screen prompts to continue through the process. INSTALL checks to make sure it is safe to remove NDS from the server. If the server holds a master replica, the utility will prompt you to place the master on another server and change this one to a read/write replica. If no downed servers or links to servers in a replica list exist, INSTALL removes NDS and deletes the Server object and its associated Volume objects from the tree. When this process is finished, press<Esc< to exit Install.
In NETADMIN or NWAdmin, confirm that the Server object and its associated Volume objectshave indeed been removed from the tree.
* Originally published in Novell AppNotes
The origin of this information may be internal or external to Novell. While Novell makes all reasonable efforts to verify this information, Novell does not make explicit or implied claims to its validity.