Backup strategy for ARM

I was trying to come up with a backup strategy for ARM. The epm backup document says take backup of both ARM database abd SOA database and files.

If I restore, both ARM\SOA databases can users jump in and continue from the point of backup. The reason I ask is that sometime back on the FCM\ARM community board I saw that restoring the database will make the period read only and user cannot change reconciliations. Does this happen if one restores both ARM\SOA dbs or does it happens if one restores only ARM db. I cannot find the discussion thread again and have to come up with a backup strategy.