Enterprise Vault maintenance on SQL Server which cause outage ?

Hi People,

How often does the EV server needs to be taken offline or all of the services is stopped so that the SQL Server maintenance can be performed based on the following Technote article:

http://www.symantec.com/business/support/index?page=content&id=TECH74591
http://www.symantec.com/business/support/index?page=content&id=TECH74666

I wonder as to why do I need to bring the EV server down first ?

Can this be done during the EV backup mode ? because my EV backup window for the Open Index and VaultStore partition takes about one week to finish.