I get Event9871 saying there is a maintenance overlap. Since I've adjusted my schedules several times leaving 30-60 minutes between maintenance jobs, I'm wondering how much time is required between jobs, or if this event is complaining about something else.I open the property pages on my mailstores and set the maintenance schedule to custom. I've confirmed there isn't an overlap in the schedule.

Hi, Please check the schedule for backup. I suspect that the backup time is over lapping the online maintenance time. Note: If you are running a backup at that time, this warning will surely be triggered because of the overlap of online maintenance and the backup job. For event 9871, We can ignore this event because that the 9871 is thrown when the schedule window for OLM has ended for a database but a transaction is still being processed. This transaction must complete, we just wont stop it because the schedule window has ended, and that is when the 9871 is thrown. Besides, we can extend the maintenance window to avoid the event id, but it just depends what we are doing when the schedule window ends, so we could still hit the 9871 event. More related information to share with you: Mailbox store online maintenance schedules overlap http://technet.microsoft.com/en-us/library/aa995795.aspx Regards, Xiu