OAB Generation Issues

We make extensive use of public folders.  Every distribution list files into a mail enabled public folder.  I’ve tried to take full advantage of 2007’s distributed architecture.  I have three clustered mailbox servers in three separate datacenters. Since CCR is not supported while hosting public folders I also have three public folder servers in each datacenter. (They host-super-huge-ginormous-mongo public folder databases. I lose sleep over this, but we’re not going there right now.) Recently I’ve seen an uptick of instances where mail enabled public folders never generate an SMTP address. Cycling the system attendant service fixes it.  There’s no indication of a problem other than getting alerted that the proxy address is not available when going to the folder permissions.

I’m slowly edging my way toward shutting down the final Exchange 2003 system. So this week I moved the Offline Address Book generator to one of the 2007 servers hosting public folders. No big deal right?  Testing in the lab, it was just a process of right click and pick an exchange 2007 server. The uptick in SA problems coincide with the OAB move. I also found 9386 and 9399 warning in the event log.

The description of the error looks like this:

OALGen is configured to generate version 2 or version 3 OAB files for offline address book '/o=Organization/cn=addrlists/cn=oabs/cn=Default Offline Address List' but there is no public folder server available. OAB versions prior to version 4 require a public folder server and cannot be generated at this time. Please ensure that a public folder server with a replica of the Offline Address Book system folder is online and mounted, or disable all OAB versions other than version 4.

Thinking back to moving the public folders (there were ~17,000 of them. ~3.5 million messages for a total of 4T of data) I double checked to make sure my OAB system folders are replicated to the 2007 public folder server.  They were. Here’s a very important piece I’ve not told you.  My public folder servers do not host mailbox databases.  I did this so that mailboxes could not accidentally be created on a “public folder” server. Keep this in mind while you read “Troubleshooting MSExchangeSA 9386 Warnings and OAB Generation and Access Issues”

Back already? My System Attendent service did NOT have a HostMDB property. If the System Attendant service does not have a host mailbox database there are quite a few actions that it cannot perform – database cleanup tasks are one, and OAB generation are another. So I quickly created a mailbox database and, using ADSIedit, gave the System Attendant a host database property.

IF you’re following along because you had the same issue, you should now see Event ID 4002’s –

An unexpected failure has occurred. The problem will require administrator intervention. The service will retry in 56 seconds. Microsoft.Exchange.Data.Storage.MailboxUnavailableException: Cannot open mailbox

 If you have ever had to move the System Attendant mailbox before then you might recognize this one.  Restart the Microsoft System Attendant service and it will create a new mailbox.

Finally I get Event ID 9331’s –

OALGen encountered error 8004010f (internal ID 501080c) accessing the public folder store while generating the offline address list for address list '\Global Address List'.

There are followed by an Event ID 9358 –

OALGen could not update the timestamp of the previous version of offline address list '\Global Address List'.  Please check earlier event log messages for the specific error.

Updating the offline address lists manually from the Exchange Management Shell using the commands below fixed these errors.

Get-Addresslist | Update-Addresslist

Get-GlobalAddresslist | Update-GlobalAddressList

Get-offlineaddressbook | update-OfflineAddressbook

Update-FiledistrubutionServer