Combining Recovery Tools

     

After you diagnose a problem, you need to work toward resolving the problem. Sometimes, though, complete recovery involves the use of multiple recovery tools because a single tool does not have the complete capability you need to resolve the issue.

Chapter 8 examines a number of different recovery tools, including the following:

  • UImport and NDS Import Convert Export (ICE)

  • SMS Backup and Restore

  • eMBox

In addition to using these tools, you can use a number of the diagnostic tools previously discussed for recovery as well:

  • DSRepair

  • DSDiag and DSBrowse

  • NetWare Administrator and ConsoleOne

  • NDS iMonitor and iManager

You might have noticed that the functions of the recovery tools overlap significantly with those of the management tools, and this is not accidental. You should try to work with all these tools on a day-to-day basis so that you are familiar enough with them to understand how they can help you during a data recovery situation. It is usually difficult to have to use a separate set of tools during data recovery, especially if you don't need to use them frequently; part of your time spent on recovery will be wasted in refamiliarizing yourself with this separate set of tools.

Chapter 11, "Examples from the Real World," provides examples in which combining recovery tools results in a faster solution than using a single recovery tool. Remember that in a disaster-recovery situation, when you have a diagnosis, you need to work as quickly as possible to resolve the problem.

Working with a combination of recovery tools requires a good knowledge of the tools themselves . If you do not know for certain what a tool does or how it can help in resolving a problem, you might end up using a tool that will get you most of the way to a complete resolution but not let you finish the job. Let's continue with the previous example of a -694 error in synchronization. DSTrace showed the object name that was causing synchronization problems, and now you need to work to resolve the issue.

The first thing you should do is to verify that the object on the server that holds the Master replica is good; if it is, you can recover the object without deleting it. You can use DSBrowse (or DSView) to examine the attribute values of this object on the Master replica to make sure they are what you expected.

NOTE

At the time of this writing, DSBrowse is not available on Unix/Linux. Instead, you can use LDAP to export an object's attribute values for examination. Examples of using LDAP to export (and import) object data from a tree can be found in the section "LDAP Import Convert Export Utility " in Chapter 12, "eDirectory Management Tools."


If, on examination, the object appears to be fine, you can run DSRepair on the server that is reporting that it lost the entry. You can select either an unattended full repair of the database or a repair of the local database from the advanced options menu. You do this to ensure that the database is consistent locally. Then you force a replica synchronization with the Master replica.

The best way to proceed is to force a synchronization of all objects within the replica. You can do this most effectively by using the Receive All Objects option in DSRepair, as illustrated in Figure 9.12. This option essentially deletes the partition from the server that is reporting the error (by changing the replica state to New) and re-creating it by using the information received from the Master replica.

Figure 9.12. Resolving data inconsistency between replicas.
graphics/09fig12.jpg

This is the least destructive of all fixes because only the replica on the problem server is affected, and the synchronization traffic is between the Master replica and the affected replica. If you use the Send All option instead, all non-Master replicas in the replica ring are set to the New state and are re-created. If the involved partition is large in size , a high volume of network traffic can result between the servers.

You could also use the advanced mode in DSBrowse to send a single object from the Master replica to the other replicas in the ring (see Figures 9.13 and 9.14). The one drawback of this is that DSBrowse is not available on Unix/Linux, where you need to use the DSRepair solution described previously.

Figure 9.13. Sending the selected object by using DSBrowse in Windows.
graphics/09fig13.jpg

Figure 9.14. Sending a selected object by using DSBrowse on a NetWare 6 server.
graphics/09fig14.jpg



Novell's Guide to Troubleshooting eDirectory
Novells Guide to Troubleshooting eDirectory
ISBN: 0789731460
EAN: 2147483647
Year: 2003
Pages: 173

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