Checkpointing a Directory

Each domain and subdomain should be checkpointed at least once every 24 hour, or more often if the transaction log grows too large in relationship to swap space or total disk space.

Checkpointing large domains, or any domain with a large transaction log, is a time-consuming process which ties up NIS+ servers and slows NIS+ service. While a server is checkpointing, it will still answer requests for service, but it will be unavailable for updates. If possible, checkpoint operations should be scheduled for times when system use is low. You can use the cron file to schedule checkpoint operations.

To perform a checkpoint operation, run nisping -C on the domain's master server. It is good practice to first ping all replicas before checkpointing. This ensures that the replicas are checkpointing data that is current and up to date.

• To checkpoint a particular directory, run the nisping command with the -C directoryname option. For example,

  rootmaster# /usr/lib/nis/nisping rootmaster# /usr/lib/nis/nisping -C org_dir

• To checkpoint all the directories in the local domain, run the nisping command with the -C -a options. For example,

rootmaster# /usr/lib/nis/nisping
rootmaster# /usr/lib/nis/nisping -C -a

Once a server has transferred information from the server's transaction log to the appropriate NIS+ tables, the transactions in the log file are erased to conserve disk space.

For example, to checkpoint all of the directories in the doc.com. domain, you would enter:

rootmaster# /usr/lib/nis/nisping -C -a
Checkpointing replicas serving directory doc.com. :
Master server is rootmaster.doc.com.
 Last update occurred at Wed May 25 10:53:37 1995
Master server is rootmaster.doc.com.
checkpoint has been scheduled with rootmaster.doc.com.
Replica server is rootreplica1.doc.com.
 Last update seen was Wed May 25 10:53:37 1995
Replica server is rootreplica1.doc.com.
checkpoint has been scheduled with rootmaster.doc.com.