Have set up Public Folder replication on Exchange 2010 (does not work out of the box, you need to set HomeMDB attribute for the SA on the Public Folder Database first), and the content is now updating so in theory have replicas on different databases. Tested this by dismounting the database on which the folders are homed, and, using OL 2007, this simply does not work - cannot expand folders.
My understanding is that the reason for this is that the clients are assigned a default PF database. If this DB is available and there is a replica, no problem. If it is available and there exists no replica, it consults its heirarrchy and chooses best referral to an existing replica based on AD site configuration and/or cost assigned to referrals. If the default DB is NOT available, it cannot be consulted for referral to a suitable replica and you get the error described earlier. So is it now simply the case that one cannot achieve true HA for Public Folders - i.e. there is no failover mechanism if the dafault PF db is down ?
Thanks for guidance