In Enterprise Vault 2007 you did not need to back up the journal vault store partitions and vault store database. In Enterprise Vault 8.0 you must do one of the following:

Enterprise Vault 2007 did not create Watchfile database records for journal mailbox items when the vault store setting for removal of safety copies was one of the following:

Enterprise Vault 8.0 always creates Watchfile database records for items from journal mailboxes, regardless of the safety copies setting.

If you allow the journal archiving to continue without performing backups, the increasing number of Watchfile records eventually causes performance problems.

See the 'Managing safety copies' section in the 'Day-to day administration' section of the Administrator's Guide

See the 'Backing up Enterprise Vault' chapter in the Administrator's Guide