Exchange 2013 Multi-Tenant Mailboxes

[awsiemieniec]

Does anyone have any whitepapers or working knowledge on what is the best practice for hosting multiple clients on a single Exchange server? In particular, I'm looking for an answer to the question: Should each tenant be in their own mailbox database or is it better practice to have a single, larger database? My gut feeling is to break out each tenant to their own DB but maybe that isn't the case.

Thanks.

 

[Snowknight26]

https://www.microsoft.com/en-us/download/details.aspx?id=36790

A properly planned and configured multi-tenant Exchange system does not need to segregate each tenant’s mailboxes onto dedicated (per-tenant) databases to achieve multi-tenancy. It is not recommended you group tenant mailboxes in specific databases for this reason, as a problem with a single database may result in a much greater impact on those tenants.

 

[awsiemieniec]

Right. I read that too. Which, to me, seems to counter all logic. What that snippet tells me is that I should have all my eggs in one basket. That's what it's saying, right? If my mailbox DB has an issue, then TenantA, TenantB... TenantN all have trouble and possible down time. If they are segregated into different DBs, then only TenantA is affected.

I followed the best practices document that you referenced when setting up the system but it seems counter-intuitive. A little while ago MS was all eager to tell us that breaking out of the Exchange roles into different areas (was that Exchange 2003?) was a best practice but now they seem to have reversed their direction, 10 years later, and "simplified" their roles into basically just two. Anyway. I appreciate your input. Thanks.

 

[bigdogchris]

Users spread across multiple databases means less chance of downtime. Maintenance is faster with smaller databases. Easier to move to new volumes. etc.