OAB

Working with Offline Address Book

This article covers steps when troubleshooting issues with the OAB in On-Prem Exchange

Prerequisites

You will need an account that has administrative access to the Exchange server

Commands

How to check the OAB update schedule

Run the following command in the Exchange console, replacing <Server name> with the name of the server

[xml]$diag=Get-ExchangeDiagnosticInfo -Server <ServerName> -Process MSExchangeMailboxAssistants -Component VariantConfiguration -Argument "Config,Component=TimeBasedAssistants"; $diag.Diagnostics.Components.VariantConfiguration.Configuration.TimeBasedAssistants.OABGeneratorAssistant

It should give you a table like the following

Classification                            : CustomerExpectation
MaxConcurrency                            : 1
Enabled                                   : True
EnabledDuringBlackout                     : False
MailboxNotInterestingLogInterval          : 1.00:00:00
SpreadLoad                                : False
SlaMonitoringEnabled                      : True
CompletionMonitoringEnabled               : False
ActiveDatabaseProcessingMonitoringEnabled : True
SlaUrgentThreshold                        : 0.1
SlaNonUrgentThreshold                     : 0.5
WorkCycle                                 : 08:00:00
GroupMailboxADGroupProcessingEnabled      : False
SpreadLoadPaddingPercent                  : 10

The WorkCycle entry in the table indicates how often the OAB is updated

How to get the last OAB update time

This command will give you all of the OABs, which one is default, and when it was last updated

Get-OfflineAddressBook | select Name,IsDefault,WhenChanged

Check the Last Update on a PC

Open the registry and browse to the following key

HKCU\Software\Microsoft\Exchange\Exchange Provider\OAB Last Modified Time

More Information