To get a valid epoch to perform the following steps:

1. Run the following command: /opt/vertica/bin/admintools -t start_db -d <DB name> -F
   
   # su - dradmin
   $ /opt/vertica/bin/admintools -t start_db -d drdata -F (where drdata is the DB name) 
   
   
2. The above command will likely fail but the act of attempting a "force" repair of the Vertica database will put an Epoch.log in the catalog directory.  This would be the same directory that contains the vertica.log
   

   $ cd /Vertica/catalog/drdata/v_drdata_node0001_catalog/ (where /Vertica is where you installed Vertica, you may have installed it in a different directory)

   $ cat Epoch.log (see one example below)

   Last good epoch: 0xa7bd6e ended at '2022-01-03 09:42:00.624987-05'
   Last good catalog version: 0x1107c3d
   K-safety: 0
   AHM: 0xa7bd6e ended at '2022-01-03 09:42:00.624987-05'

3. Take the hexadecimal number in Epoch.log and convert it to a decimal number.  You can use the following URL to make the conversion: http://www.binaryhexconverter.com/hex-to-decimal-converter
   
   a7bd6e (hexadecimal) --> 10993006 (converted to decimal)
   
   
4. Now open adminTools on the Data Repository
   • Choose #7 Advanced Menu
     
   • Choose #1 RollBack Database To Last Good Epoch
     
   • Choose the database in question
     
   • The converted number from step #3 should match what is in the "Restart epoch" field
     
   • Choose OK if it does.
     
     If it does not, especially if the Restart Epoch is zero, do not proceed, select cancel and contact support.
     
     
5. The database should now start successfully