We help IT Professionals succeed at work.

Exchange 2010: Mailbox Resiliency

InfoTechEE
InfoTechEE asked
on
In reviewing this link, I'm having a hard time understanding the benefits for us with Mailbox Resiliency. http://www.microsoft.com/exchange/2010/en/my/mailbox-resiliency.aspx

We want to get a new server for our company with Exchange 2010. It's a small company of about 50 - 100 employees. It will be a single server setup. We do however, have a Disaster Recovery Exchange server in our other Data Center that uses Double-Take replication software to fail-over in case of a disaster or power outage.

So my question is, for a small company in a single Exchange server scenario, what are the benefits to us in terms of "Mailbox Resiliency".
Comment
Watch Question

Commented:
Well exchange 2010 will do what double take is doing but it will do it properly. You must value your email as you have a solution already do en exchange 2010 dag containing two multirole mailbox, cas and hub servers, one in each site.

Going this route would be a fully supported solution that really a dr solution akin to what you already have.

Author

Commented:
My main goal is to accomodate certain users with HUGE mailboxes. These users never delete a single email, so each year they add about 50,000 emails to their mailbox. It's about 10GB mailbox size.

That's why I thought Mailbox Resiliency sounded like it can accomodate such users, but in the link I sent, none of the features seem to talk about large mailboxes.
Maen Abu-TabanjehNetwork Administrator, Network Consultant
Top Expert 2011

Commented:

Commented:
You are bordering your mailboxes folders critical item limits which for exchange 2010 is 100k items per mailbox. Critical folders are the main inbox, sent items, deleted items etc, a mailbox shouldn't exceed these limits or store corruption can occur.

I would seriously look at the archiving features of exchange 2010 to reduce the numbers.

The size of a single mailbox isn't really an issue for database availability groups, databases can grow upto 2tb when in a dag so that's lots of storage for your 100 users. A simple two node dag would act just like your double take solution does, you would have a complete offsite copy if your data. And backups of the other roles such as the client access which is used to connect users to their mailboxes or the hub transport which routes mail.  

Author

Commented:
OK, if we forget for a second about the 2nd Exchange server in the Data Center, and consider our setup as a single server Exchange setup, would Mailbox Resiliency be of any benefit to us?
Commented:
Resiliency is only effective if you can eliminate single points of failure.

Author

Commented:
MAILBOX resiliency sounds like some kind of feature that offers protection on a mailbox level. For example, a copy of the mailbox on the same server in case the original mailbox should become corrupt or something else.

Commented:
Well I'm exchange 2010 dags your databases are resilient if you have multiple copies located in the same site. Unlike previous versions of exchange, if a single database failed this would cause the whole cluster to fail over. In exchange 2010 if a database fails then only the database that's failed would fail over. If your spanning sites then this is no longer the case and you would need to fail over the entire server again. So usually it's common to say multiple copies in the same site is HA or high availability where as relying on a copy in a different site is DR or disaster recovery. Of course you can have ha copies available in a different site but when a mailbox moves sites this usually requires outlook to log out and back in again.