Taking Content Databases Offline

Our SharePoint 2010 Content Databases are in a seperate clustered SQL Server 2008 R2 environment. We need to take all of our database servers offline (shut them down) for a short time to facilitate migration to a new SAN. No problem with the SQL instance -- that'll all remain the same name, etc.

What type of impact will it have on SharePoint 2010 to have the databases offline for up to an hour? Is it recommended that the Web Front Ends and Application Server be shut down prior to taking the SP databases offline, or if the SharePoint servers are left running, will any SP services need to be restarted or will SP recognize the databases when they come back online? e.g., will SharePoint be able to recover on it's own if left running during the database downtime or should the databases be taken offline within SharePoint first? Any other prep on the SharePoint side prior to shutting off the database servers? This work will be done after hours of course.