In the zope.conf file, verify that the client zeo1 line is commented out, as follows:

<zodb_db main>
  mount-point /
  # ZODB cache, in number of objects
  cache-size 5000
  <zeoclient>
    server localhost:8100
    storage 1
    name zeostorage
    var $INSTANCE/var
    # ZEO client cache, in bytes
    cache-size 20MB
    # Uncomment to have a persistent disk cache
    #client zeo1
  </zeoclient>
</zodb_db>

As the zenoss user, enter these commands to remove old caches, if they exist:

zenoss stop
rm $ZENHOME/var/*.zec
zenoss start

Download and save the PreUpgrade30 ZenPack .egg file from the Zenoss Community ZenPacks page:

community/zenpacks

Run the following command as the zenoss user:

zenpack --install ZenPacks.zenoss.PreUpgrade30

Enter the following commands:

zopectl stop
zenhub stop
zopectl start
zenhub start

Run the following command to build the catalog:

zencatalog start

When the zencatalog daemon starts, it will traverse your database and build the catalog.

You can check the progress of the daemon from the event console, or from the zencatalog.log file. Run the following command:

tail -f $ZENHOME/log/zencatalog.log

As the zenoss user, use the following commands to back up the  Zenoss files. Use both backup methods for maximum recovery options.

zenoss$ zenbackup --save-mysql-access --file /tmp/zenoss-backup.tgz
zenoss$ tar czf complete-backup.tar.gz $ZENHOME

Save the backup files to a location other than $ZENHOME.