; Creating the DAG

Transcription

1 Dean Suzuki Blog Title: Creating An Exchange 2013 Database Availability Group Created: 11/30/2012 Description: Today, I am going to build a 2 node Exchange 2013 DAG. Two nodes is not the recommended number of nodes for a production deployment, but I chose this number as the minimal number of nodes to get experience building a Database Availability Group on Exchange References: ; Creating the DAG Disclaimer: Contents of this blog and article represent the opinions of Dean Suzuki, and do not reflect the views of my employer. (C) 2012 Dean Suzuki, All Rights Reserved Procedure: Table of Contents 1 Prepare File Share Witness Server Create the Cluster Network Object (CNO) Create DAG Adding Exchange servers to the DAG Adding Database Copies... 12

2 1 Prepare File Share Witness Server The first step is to pick a server to hold the file share witness. Since the DAG is a cluster, it uses a file share witness when there is an even number of nodes in the DAG to check and maintain quorum. Typically, the recommendation is to put the quorum on a CAS server. However in my lab, I have two Exchange 2013 CAS/Mailbox combo servers. So, I decided to put the quorum on another server in my lab. In order for Exchange to create and write the data to the file share witness, it needs rights on the server so the first step is to add the Exchange Trusted Subsystem group to the local administrators group on the server. 2 Create the Cluster Network Object (CNO) The documentation is slightly confusing currently on when you should pre-create the cluster network object. See

3 I thought that I didn t need to do it for my lab since my domain controllers are running Windows However after doing some research, the recommendation was to go back and pre-stage the Cluster Network Object (CNO). After I went back and did that, the installation went fine. Note: In my lab, Exchange pre-created the CNO object in AD, but it had some incorrect permissions. I tried to modify the incorrect permissions to the permissions documented. However even after doing that, I wasn t able to create the DAG. So, I went back and deleted the CNO in AD and manually created using the procedure documented above and the DAG creation went fine. According to ( perform the following steps: 1. Open Active Directory Users and Computers. 2. Expand the forest node. 3. Right-click the organizational unit (OU) in which you want to create the new account, select New and then select Computer. 4. In New Object - Computer, type the computer account name for the CNO in the Computer name box. This is the name that you'll use for the DAG itself. Click OK to create the account. 5. Right-click the new computer account, and then click Disable Account. Click Yes to confirm the disable action, and then click OK.

4 6. If Advanced Features aren't enabled, turn them on by clicking View, and then clicking Advanced Features. 7. Right-click the new computer account, and then click Properties. 8. In <Computer Name> Properties, on the Security tab, click Add to add either the computer account for the first node to be added to the DAG or to add the Exchange Trusted Subsystem USG: 1. To add the Exchange Trusted Subsystem, type Exchange Trusted Subsystem in the Enter the object names to select field. Click OK to add the USG. Then select the Exchange Trusted Subsystem USG and in Permissions for Exchange Trusted Subsystem field, select Full Control in the Allow column. Click OK to save the permission settings. 2. To add the computer account for the first node to be added to the DAG, click Object Types. In the Object Types dialog box, clear the Built-in security principals, Groups, and Users check boxes. Select the Computers check box. Click OK. In the Enter the object names to select field, type the name of the first Mailbox server to be added to the DAG, and then click OK. Then, select the first node's computer account, and in the Permissions for <NodeName> field, select Full Control in the Allow column. Click OK to save the permission settings.

5 Adding Exchange Trusted Subsystem and then check Full Control

6 Adding Lab2012-E2013 which is one server that I want to add to my DAG. Adding lab2012-e2013b which is one server in my DAG. 3 Create DAG (from 1. Login to the new Exchange Admin Center at:

7 2. In the EAC, go to Servers > Database Availability Group. 3. Click to create a DAG. 4. On the new database availability group page, provide the following information for the DAG: o Database availability group name Use this field to type a valid and unique name for the DAG of up to 15 characters. The name is equivalent to a computer name, and a corresponding Cluster Network Object (CNO) will be created in

8 Active Directory with that name. This name will be both the name of the DAG and the name of the underlying cluster. o Witness server Use this field to specify a witness server for the DAG. If you leave this field blank, the system will attempt to automatically select a Client Access server in the local Active Directory site that is not installed on a computer with the Mailbox server to be used as the witness server. Note: If you specify a witness server, you must use either a host name or a fullyqualified domain name (FQDN). Using an IP address or a wildcard name isn't supported. In addition, the witness server cannot be a member of the DAG. o o Witness directory Use this field to type the path to a directory on the witness server that will be used to store witness data. If the directory doesn't exist, the system will create it for you on the witness server. If you leave this field blank, the default directory (%SystemDrive%\DAGFileShareWitnesses\<DAG FQDN>) will be created on the witness server. Database availability group IP addresses Use this field to assign one or more static IPv4 addresses to the DAG. Enter an IPv4 address and click to add it. Leave this field blank if you want the DAG to use DHCP to obtain the necessary IPv4 addresses. 5. Click Save to create the database availability group.

9 Note: I got errors creating the DAG if I specified an IP address. So, I went back and removed the IP address and it created fine. I am not sure why the process was throwing an error when I set an IP address in the web interface. I guess if you need to specify a static IP address for the DAG then I ll need to do it through the powershell. Note: There was a warning on enabling WMI access through the firewall on the witness server so I went to the witness server and allowed WMI access in the firewall tool.

10 4 Adding Exchange servers to the DAG Now that the DAG container is created, the next step is to add the Exchange servers to the DAG. The following steps were taken from: 1. In the EAC, go to Servers > Database Availability Group. 2. Select the DAG you want to configure, and then click.

11 o To add one or more Mailbox servers to the DAG, click, select the server(s) from the list, click Add, and then click OK. (Added my first Exchange server, Lab2012-e2013. I like to add one server at a time to the DAG) o To remove one or more Mailbox servers from the DAG, select the server(s) and then click the minus (-) icon. 3. Click Save to save the changes. 4. When the task has completed successfully, click Close. I went back and added the second server to my DAG, lab2012-e2013b.

12 After this step, you should have a DAG with the two servers as member servers. 5 Adding Database Copies Now that we have created the DAG and added Exchange servers to the DAG, the next step is to add database copies. The following steps were taken from: 1. In the EAC, go to Servers > Databases. 2. Select the database that you want to copy, and then click.

13 (Note: You need to click the before the submenu appears with the option to Add database copy) 3. On the add mailbox database copy page, click browse..., select the Mailbox server that will host the database copy, and then click OK. 4. Optionally, configure the Activation preference number for the database copy.

14 5. Click More options to designate the database copy as a lagged database copy by configuring a replay lag time, or to postpone automatic seeding of the database copy.

15 6. Click Save to save the configuration changes and add the mailbox database copy. 7. Click OK to acknowledge any messages that appear. Note on the side menu when I select the database, Exchange shows that there are two servers with a copy of that database. It also appears in the middle section in the column Servers with copies

16 In contrast when I select a database where I didn t add a copy (see below), it only lists the one server that has a copy of that Exchange database.

17