Backing Up and Restoring NDS for Planned Hardware Upgrades
Novell Cool Solutions: Feature
By Todd Grant
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Posted: 25 May 1999
There are times when a NetWare 4.11 server requires a hardware upgrade. For example, the server may have an old hard disk drive where volume SYS is located. In situations such as this, you don't need to uninstall NDS from the server. You can use INSTALL.NLM to save NDS information before the hardware upgrade and to restore NDS information after the upgrade.
Two options in INSTALL help you back up and restore. The Save Local DS Information Prior to Hardware Upgrade option prepares the NDS information on the server prior to the upgrade. When you select this option, INSTALL creates a file called BACKUP.NDS in the server's SYS:SYSTEM directory. BACKUP.NDS stores all the NDS information for this server, including replica information.
This option also locks and disables the NDS database on this server, preventing certain NDS operations on this server 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 synchronize the NDS database on this server to the other servers in the tree.
The Restore Local DS Information after Hardware Upgrade option uses BACKUP.NDS to restore NDS information on the server. Before the NDS information is restored, INSTALL verifies that the server is in the same relative state as before the upgrade. INSTALL verifies the server's object and authentication keys still exist and that the server still exists in all the replica rings for replicas that were on this server before the upgrade.
Before You Begin
Before you begin the backup and restore process, there are some things you must do.
- 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. (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.)
- 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 documentation for instructions.)
- 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 --601 error during the Restore phase and the process will not be completed.
- Make sure you have a current tape backup of the entire server.
- If the server to be upgraded contains the master replica of your NDS tree, you will need to move the master replica to another server. (You can determine if the server to be upgraded contains the master replica and, if necessary, move the master replica to another server by using DSREPAIR.NLM.
- 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.
- If you already have a current tape backup of the file system, log in from a client workstation as Admin and map a drive to the root of the SYS volume on the server to be upgraded. Then skip to Step 3.
Once the backup is performed, you CAN NOT map drives to volumes or authenticate to the server to be upgraded. It is very important that you have a drive mapped to the SYS volume on the server prior to beginning the backup process.
- If you don't have a current backup, use an SMS-compatible backup program to do a file system backup of the server's volumes.
- Load INSTALL and select Directory Options, Directory Backup, Restore Options and Save Local DS Information Prior to Hardware Upgrade, 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. In most cases, the NDS database will not fit on a floppy. Press F3 to specify a different path. You might want to specify a temporary directory on the local hard drive of your workstation. If you are copying the file to another server, 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.
- Reinstall NetWare 4.11. When you are prompted to select an NDS tree, don't. Instead, press F5,and then press F3.
- Select Restore Local DS Information after Hardware Upgrade. When prompted for the file path, press F3 and enter the path to BACKUP.NDS. If you copied BACKUP.NDS to a second server, you might need to 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. Restore data to any volumes affected by the hardware upgrade.
Remove a Server from the Tree
What if you have a NetWare 4.11 server you want to upgrade but you don't care about saving the NDS information on that server? In this case you need to remove that NetWare 4.11 server from the network, and there is a proper way to do this. Don't just disconnect the server from the network! If a server is removed incorrectly, it could cause NDS synchronization problems. It is important to remember that NetWare 4 is a distributed network environment in which servers are constantly communicating with each other. If you need to permanently remove a functioning NetWare 4 server from an NDS tree, it should be done properly using INSTALL.NLM.
- Load INSTALL.
- From the Installation Options menu, select Directory Options (Install NetWare Directory Services) Remove Directory Services from this Server." Answer "Yes" to the confirmation prompt, and type the password for an administrative user when prompted.
- Respond to the prompts to continue through the process. INSTALL checks to ensure it is safe to remove NDS from the server. If the server holds a master replica, the utility will take care of placing the master on another server and changing 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 NetWare Server object and its associated Volume objects from the tree.
- Press Esc to exit INSTALL.
- In NetWare Administrator, confirm the NetWare Server object and its associated Volume objects have been removed from the tree.
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