hi , 

i have currently exchange 2013 running on two node EXCH01(CAS/Mailbox) and EXCH02(CAS/Mailbox) and we are planning to add another Exchange node on DR site , the new Exchange Node will have all the role together . is there any concern i need to keep in mind before proceed with  my deployment ? for me i will do the following :

Install the new exchange server 

add new exchange server to mailbox DAG 

add new exchange server to NLB

configure send/receive connector

is there any other things i have to care about .?

thanks all 

Hi

Are you going to have your witness server in a 3rd site and are you going to look at DAC mode at all and an alternate witness?

hi , 

thanks for your reply , i have two site the main site and the DR site , what do you mean by ( are you going to look at DAC mode at all and an alternate witness? ) 

DAG and NLB is already set and configured what is need to do is to add the new Exchange node to both DAG and NLB

Hi

DAC (Data Center Activation Coordination) will stop the split-brain syndrome between a stretched DAG like you have, meaning if you lose DC1 and the DB's activate on the secondary DC, when DC1 comes back online and as it is where quorum will be due to the witness server you wont have the DB's trying to mount there either.

hi , 

really appreciate your useful information , what is the best practice in such case ?

thanks 

There isn't really any "best practise". DAC mode is either on, or off.
In this scenario you want to turn it on.

https://technet.microsoft.com/en-us/library/dd979790%28v=exchg.150%29.aspx

Simon.

Hi JavaHeart,

If you choose not to use DAC mode, you still need a witness server for DAG to function properly incase of a failure. Utizing the Dynamic Quorum model in WindowsServer2012.

Use this to find the current automatically assigned Witness when you setup the DAG.

Get-DatabaseAvailabilityGroup -Identity DAG -Status | fl

For Deploying a new Exchange server, its advisable to start it in a new AD site(without any client traffic) and once all set, move it back to the destination site where you want it.

Else you might end up, clients connecting to the half setup server with incomplete certificate pop-ups.

Hi,

If you want to add new Exchange server in DR site, the basic requirement includes:

1 DC, 1 CAS and 1 MBX (or one Exchange server including both CAS and MSX role)

For detailed information about this, please refer to:

Planning for High Availability and Site Resilience

https://technet.microsoft.com/en-us/library/dd638104(v=exchg.150).aspx

Regards,

hi , 

ok if i am not going to add this node to DR site i just want to add another node to my current exchange environment which is ( two node each has CAS/ MBX ) what should be keep in mind in such case ?

Thanks  

If you are just adding another server in the same site, then there isn't much to worry about at all.
The most to be concerned about is email flow - so if you have restrictions on the Receive Connectors then they need to be adjusted. Otherwise it comes down to whether it is going to be exposed to the internet or not, which will drive the CAS configuration.

Simon.

Dear JavaHeart;

Good question, and if want to get all details about Exchange 2013 DR and the high availability you need to check the below articles.

Planning for high availability and site resilience

Datacenter Switchovers

Hi JavaHeart,

This applies to all installs: DR - non DR

For Deploying a new Exchange server, its advisable to start it in a new AD site(without any client traffic) and once all set, move it back to the destination site where you want it.

Else you might end up, clients connecting to the half setup server with incomplete certificate pop-ups.