My question is pretty simple, i'm sure it's a simple answer. With exchange 2010 enterprise, there is technically no limit on database sizes. I was watching Ross Smiths presentation at TechED "Designing Microsoft Exchange 2010 Mailbox High Availability for Failure Domains" And he talks about creating 100's of databases I have never come close to using that many, at most 5. So i believe i am not understanding Best Practices on WHEN to create a new mailbox database, or how many mail databases you should have based on number of mailboxes, etc. I am looking for that design guidance and best practices. Any help, dialog or links are much appreciated thank you

The answer is.....It depends on your requirements. You create new Database when you see that there are lots of Mailbox in on database and you want to split across the database etc. Gulab | MCITP: Exchange 2010-2007 | Lync Server 2010 | Windows Server 2008 | Skype: Exchange.Ranger | Blog: www.ExchangeRanger.Blogspot.com

Yes this would really depend on a number of factors such as the mailbox/database sizes. This is important becuase you need to consider the time it takes to restore the databases from backup and the SLA's you may need to meet. Also, if this is a DAG, CCR you need to think how long it may take to reseed the databases and you may want to limit the size of them. Other factors could be administration such as quotas, mailbox mangement etc. Hope this helps.

I am looking for that design guidance and best practices. Hi Skalinator, You can also try the Exchange 2010 Mailbox Server Role Requirements Calculator: http://blogs.technet.com/b/exchange/archive/2009/11/09/exchange-2010-mailbox-server-role-requirements-calculator.aspx Frank Wang Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

Well, the point is to find a balance between the databases (size and users per db) And if you're not using native data protection, then there are some other considerations to be aware of like backup schedule / time Even if you're having large databases, the backup should still be able to take full backups during the backup window The best suggestion is to use the calculator above Jonas Andersson | Microsoft Community Contributor Award 2011 | MCITP: EMA 2007/2010 | Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82

Hi Skalinator, Any updates? Frank