NetBase for MPE Reference Guide

NetBase Shadowing
5-23
Sync or Discard State
Shadow files that are in either an S (out of sync) or D (discard) state, must be resynced. Resyncing a
shadow copy involves refreshing the data on the shadow system with a copy of the data from the
master system.
To resync:
1. On the master system, stop access to the data. You must do this to create a store of the data.
2. On the shadow system, stop the posting process:
:RUN NBCTRL.PUB.NETBASE;INFO=”STOP POST”
This needs to be done to ensure that all subsequent updates to the master are preserved in
Import Queue files.
3. On the master system, store copy of the data. This will be used to refresh the shadow copy.
4. On the master system, allow access to the data. Updates will now be sent to the shadow system
5. On the shadow system, restore the data either using NBSYNC or the RESTORE Utility. If you use
NBSYNC to do the RESTORE, it will automatically specify the OLDDATE option when doing the
RESTORE. If using RESTORE or a Third Party Utility, be sure to specify the OLDDATE option. The
LAST MODIFY TIMESTAMP on the file label is used as the RESYNC time. If the OLDDATE option is
not used, the wrong resync time will be used and the shadow file will go out of sync again.
6. On the shadow system, run NBSYNC to reset directory flag and set resync timestamp:
:RUN NBSYNC.PUB.NETBASE,RESET
If NBSYNC was used to do the restore, this step is not necessary. However, if RESTORE or a
Third Party Utility was used, this step must be done in order to reset the sync flag and set the
resync time.
7. On the shadow system, start the posting process:
:RUN NBCTRL.PUB.NETBASE;INFO=”START POST”