Although synthetic time might sound like something out of an H.G. Wells novel, it’s alive and well on many NetWare servers. Of course, I’m talking about the very vital tool that Novell Directory Services uses to protect NDS objects from receiving time stamps from the future.
Having trouble adjusting to synthetic time?
I know it sounds a little like a science fiction tale, but synthetic time errors can occur when a NetWare server with an NDS replica is brought online with an older time than the replica time stamp. When the replica time stamp is compared to the server time, the replica time stamp is found to be in the future and a synthetic time error is generated.
Synthetic time errors can also occur when a NetWare server is brought online with a time set ahead of the replica time stamp. A network administrator may notice the error and manually correct it. But that will cause synthetic time errors because the replica contains time stamps that were created before the server time was corrected. After the server time has been set backward, these time stamps are then in the future, compared to the server’s time.
Make it stop!
What can you do to silence the annoying beeps that your server makes when the synthetic time errors are generated every two minutes? Often, the answer is, simply, nothing. If the time stamps are not set too far ahead, eventually the server’s time will catch up to the future time stamp and the error message will no longer be generated. You can use this approach if the time stamp is no more than a few days in the future.
A far more aggressive approach to correcting synthetic time errors is to use DSRepair. The procedure changes the master replica’s time stamp to the current system time, and then it changes all replicas in the replica ring to a “New” replica state. The master replica then sends copies of the corrected replica to all of the servers in the replica ring.
When’s the right time?
Depending on the size of your network, replication can generate a tremendous amount of network traffic, which will easily overload slow WAN links. You might want to wait until after business hours or during low traffic times to perform this procedure.
How do I do it?
Use the following steps with DSRepair to correct synthetic time errors that are more than a few days out of sync:
- Ensure network time is correct and synchronized.
- Check that the DSTRACE screen shows “All processed=Yes” to make sure that all replicas are synchronizing.
- From the console prompt of any server in the replica ring, type LOAD DSREPAIR -A.
- Select the Advanced Options menu.
- Choose Replica and Partition Operations.
- Select the partition generating the synthetic time errors.
- Select Repair Time Stamps And Declare A New Epoch.
- Log in as Admin or an equivalent user.
While synthetic time may sound intriguing, it is extremely important to the NDS database. Without it, the NDS could quickly become inaccurate or corrupt. Even though the best course of action may be to do nothing, all synthetic time errors should be treated as a potentially serious threat to the stability of the NDS.
Steve Pittsley is a desktop analyst for a Milwaukee hospital. He has a loving wife, three wonderful children, and enjoys playing drums, bowling, and most sports.There's no reason not to get exactly what you want from TechRepublic. By becoming a volunteer member of AdminRepublic's Virtual Advisory Board, you can help guide our Web site by giving us your opinions on the topics and features you need as an elite member of the IT admin community.Member responsibilities include:
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