Dears, We have Exchange 2007 SP1 with CCR in windows server 2003 SP2 I have the following event logged MSExchangeIS (8624) First Storage Group: Online defragmentation is resuming its pass on database 'T:\Program Files\Microsoft\Exchange Server\Mailbox\First Storage Group\Mailbox Database.edb'. This pass started on 12/23/2010 and has been running for 21 days. why does it take that much time, even I have schedule it to run for 9 hours daily the size of the database is about one Tera and there is another database with size 100 GB that logs the following events MSExchangeIS (8624) Third Storage Group: Online defragmentation is resuming its pass on database 'T:\Program Files\Microsoft\Exchange Server\Mailbox\Third Storage Group\Second Mailbox Database.edb'. This pass started on 1/9/2011 and has been running for 5 days. and it runs for 2 hours daily could you please advise Best Regards,

Thanks for replying I have posted that there is another database with size 100 GB that logs the following events MSExchangeIS (8624) Third Storage Group: Online defragmentation is resuming its pass on database 'T:\Program Files\Microsoft\Exchange Server\Mailbox\Third Storage Group\Second Mailbox Database.edb'. This pass started on 1/9/2011 and has been running for 5 days. and it runs for 2 hours daily so I think there is another problem different than size ? right ? We will update soon , but I prefer if I can solve this issue before upgrade Thanks

With 1 TB store its expected. With 100 GB store also its expected. So best possible solution will be to break the 1 TB and 100 GB databases in to smaller ones. And give some more time for Online Maintanence. Also make sure that there is no other activity going on the server when the Online maintanence is running.

ok.please increase the online maintainence interval window. it is okay that large databases take long time to complete online defrag Dhruv

If both of those databases are on the same server, then I am not surprised that they are taking a long time - no matter what the size. The disk subsystem must be thrashed. This unfortunately sounds like a poorly designed Exchange environment and therefore not working correctly should be expected. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources