Why do I have to lock vobs prior to backing them up?
You must lock vobs to keep the database consistent with the storage containers where all the data (element versions) is stored. Write operations which occur during the backup break the consistency, the keys in the database are not fully correct and you may have trouble accessing certain elements. You can use cleartool checkvob -pool -source to check for errors. Remember, inconsistencies in the database are hard to notice without the cleartool checkvob command. You might think that everything is okay but months later you will run into problems.
