During a disaster recovery test, we noticed some loss of funtionality
of public folders and, as a result, OWA.
We are running Exchange 5.5 SP4 in the following manner:
5 dedicated mailbox servers (no public folders used here)
3 IMC / Public folders servers
2 OWA servers (only running the OWA component)
All the mailbox server's have the Private IS setting for Default Public
folder server set to "PFServer1". All of the public folders under
Folders->Public Folders are replicated to both "PFServer2" and
"PFServer3". The resources are present on each replica and replication
status is Up to date.
Here was the problem we had:
We failed over the 5 mailbox servers to our remote datacenter (the
mailbox servers are mirrored asynchronously using DoubleTake); this
worked fine - they were all funtional and mail flow was normal across
the IMC which was PFserver3 . Now, when we removed communication from
the remote datacenter to the original datacenter, outlook clients would
open their mailbox store but would complain that PFServer1 was not
available - the result, we couldn't open public folders from the outlook
client. Also, OWA stopped functioning as well. We oringinally thought
it to be a domain authentication issue; however, on closer inspection,
we noticed that the OWA server was trying to communicate,
unsuccessfully, with PFServer1. As an experiment, we changed the
"Default Public folder server" on the IStores to the server that was
accessible - PFServer3 and all was well.
I was under the impression that the Outlook client (owa included) would
use an algorithm to determine the location of another public folder
server should the default go offline; and further, that this would be
transparent to the user and changes replicated back after the original
public folder server came back online.
Can anyone help ? I cannot find any technet / google entries describing
PS> all ex servers on Windows NT 4.0 SP6a