If you would like to be notified of when Anderson Patricio releases the next part in this article series please sign up to our MSExchange.org Real Time Article Update newsletter.
If you would like to read the other parts in this article series please go to:
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 1)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 2)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 3)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 4)
Introduction
So far, in this series, we covered several steps to build the protection of Exchange data in Backup Vault in Azure. We started by creating the connection between on-premises DPM with Backup Vault in Microsoft Azure, then we started the protection of Exchange workloads (Mailbox Databases). In the last two articles of the series we worked on two different approaches to restore data directly from Backup vault (entire database and mailbox/message restore respectively).
All that is imperative to understand in order to manage the Exchange protection, however the administrator must be aware of one key component, which is the DPM Database. In order to be able to restore and keep the protection, the administrator must keep a strategy to protect that database at all costs.
Understanding some scenarios where there is a major failure
Since we are talking about DPM database, we could go over a couple of scenarios to make sure how DPM and Microsoft Azure can help your environment to recover from a disaster.
Scenario #01 – Domain Controller failure…
A Domain Controller failure is not a big deal if you have more than one. If you have a single domain controller and that one is gone, then you have a huge problem on your hands, since the Active Directory is the core pillar for both Exchange and DPM.
The best practice is to keep at least two (2) Domain Controllers available at all times on the primary site.
Scenario #02 – DPM major failure…
If DPM is beyond recovery and we do not have access to the information, we must guarantee that we have the DPM Database available to restore the information. Since the DPM database is hosted on an SQL server which can be sharing the same server with DPM or on a remote instance, the administrator must plan that protection carefully.
We are going to cover the DPM Database protection and restore in the following section.
Scenario #03 – Exchange Server is gone…
As long as we have Active Directory, we can use /RecoverServer switch (I covered this specific topic on this MSExchange.org article), and restore the actual information using DPM from either short-term (on-premises) or long-term (Azure) locations which was the topic of the third article of this series.
Scenario #04 – Site is down for good, and all hell broke loose
In that situation, the site is completely down and there is no access to the servers for a long period of time (catastrophic situations such as fire and flood), in that case the Azure Backup will not help right away because a complete Disaster Recovery is required.
In order to be prepared for this type of situation, the administrator must build before the disaster strikes, and all components should be built with high availability/resiliency in mind.
A cost effective solution is to have a second site for the Active Directory, this way the process to restore Exchange Server and DPM would be simplified. In the same line of thought, a secondary DPM could be used to protect the primary DPM server.
Some companies do not spare a second site, and Microsoft Azure becomes an interesting option where a remote site can be configured using IaaS (Infrastructure as a Service) to build additional domain controllers. As part of the process of creating Microsoft Azure as a secondary site, a connection between Microsoft Azure datacenters and on-premises will be required, and this can be accomplished using VPN connection or ExpressRoute (more reliable solution).
Protecting a DPM Database…
There are several ways to protect the DPM database, we will use one of the simplest methods, which is creating a backup job on SQL, and the result will be that a .bak file of the database will be generated in a folder. After that point, it is recommended to move that file to another location, which can be through scripts or another backup solution.
The first step is to open the SQL Management Studio, expand Management, right-click on Maintenance Plans, and then click on Maintenance Plan Wizard, as shown in Figure 01.
Figure 01
In the initial page of the wizard, just click Next.
In the Select Plan Properties page. Assign a name, and define a schedule for the maintenance to run, and click Next (Figure 02). For this exercise, we will be creating a backup every 15 minutes of the database, in a production environment we can configure once a day or perhaps twice a day.
Figure 02
In the Select Maintenance Tasks page. Select Backup Up Database (Full) and click Next.
In the Select Maintenance Task Order page. Click Next.
In the Define Back Up Database (Full) Task page. Click on Specific Databases and select only DPMDB_<ServerName> from the list, as shown in Figure 03. In the same page, click on Backup up databases across one or more files, click add, define a folder and file name for the backup (in this article we will use the database name which is dpmdb_tordpm01.bak).
Figure 03
In the Select Report Options page. Uncheck all options and click Next.
In the Complete the Wizard page. Click on Finish. A new wizard displaying each step that is being created will be displayed, wait for its completion and click Close.
At this point, we configured the maintenance task to have a backup running on a specific interval, however we must avoid the disk being filled up with DPM Database backups. To avoid such situation, we are going to drag the item Maintenance Cleanup Task from the left to the right side, and then create a connection from the existent box (Backup Up Database) to the new box that we have just added, as shown in Figure 04.
Figure 04
Double click on the Maintenance Cleanup Task box, select the option Search folder and delete files based on an extension, and select the folder where we previously defined the location for the database backup, type in BAK on the File extension field (Figure 05). Finally, select the option delete files based on the age of the file at task run time, and define the age limit to delete the backup files. Click OK.
Figure 05
Click on Save to save all settings to the maintenance plan, and close SQL Server Management Studio. In the folder that we defined, the backup files will start showing up based on the frequency that was defined in the backup job inside of SQL (Figure 06).
Figure 06
Before we start the disaster recovery process, let’s check the protection groups in place in the DPM Server (Figure 07).
Figure 07
Restoring a DPM Server…
In a situation where the DPM Server is completely lost, and is beyond regular recovery of the disks. The recovery process of the server will follow these main tasks:
- Using Active Directory Users and Computers, locate the computer object of the DPM server and reset the object account
- Build a new Windows Server (same Operating System version from the previous DPM Server) and install all the updates available
- Join the new server to the domain
- Install DPM Server using the same settings from the original server (if the original DPM had collocated SQL, then do the same on the new server)
- Install the same patches and Cumulative Update that we had on the old server on this new DPM Server
- Assign the disks to the DPM Server
- Add the disks to the pool
If everything went fine on the steps above, a brand new DPM server is up and running. However, it does not have any previous information since it is a brand new installation.
In order to restore the DPM database, the first step is to stop all DPM Services on the new server (Figure 08).
Figure 08
Open SQL Server Management Studio, right-click on Databases and then click on Restore Database… (Figure 09)
Figure 09
In the new page, select device and select the .BAK file created on the original server (Figure 10). Click on Options tab, select Overwrite the existing database (WITH REPLACE) and click on OK. A new dialog box informing that the restore was completed successfully will be displayed, just click OK.
Figure 10
We must run two commands on DPM to complete the recovery. The first one is to synchronize the restored databases (Figure 11).
Dpmsync.exe -sync
Figure 11
The second command will create all volumes to accommodate the protection of the agents (Figure 12)
Dpmsysnc.exe -reallocatereplica
Figure 12
The result of the operation that we have just done will be the disk having the volumes based on the protection groups (Figure 13).
Figure 13
The Protection Groups will be available on the DPM Administrator Console (Figure 14), they will require a consistency check since the server is brand new, and there is no information on the storage pool (disks) in DPM.
Figure 14
That will take care of the main things to get the DPM server back to life, however, from the Exchange/Azure perspective there are a few points that must be addressed, as follows:
- Reconnect to Azure
- Since that is a new DPM installation we need to copy ese.exe and ese.dll to the DPM Server
Conclusion
In this article, we went through the process to protect and restore the DPM Database.
If you would like to be notified of when Anderson Patricio releases the next part in this article series please sign up to our MSExchange.org Real Time Article Update newsletter.
If you would like to read the other parts in this article series please go to:
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 1)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 2)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 3)
- Exchange Server 2013 offsite protection using DPM and Microsoft Azure (Part 4)
