Microsoft Hyper-V Replica for Disaster Recovery

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1 Microsoft Replica Overview Microsoft Hyper-V Replica for Disaster Recovery Spring NETA 2015 Andy Boell ESU 2 With Hyper-V Replica, administrators can replicate their Hyper-V virtual machines (VM) from one Hyper- V host at a primary site to another Hyper-V host at the Replica site. This feature lowers the total cost-ofownership for an organization by providing a storage-agnostic and workload-agnostic solution that replicates efficiently, periodically, and asynchronously over IP-based networks across different storage subsystems and across sites. This scenario does not rely on shared storage, storage arrays, or other software replication technologies. ( The Disaster Recovery & Business Continuity Problem Disaster Recovery (DR) and Business Continuity (BC) can be expensive. The smaller the planned down time is an indirect correlation to cost to achieve that. Nobody wants to be down, but schools have a hard time paying large sums of money for a what-if, especially if they ve never before experienced any measurable down time. The major associated costs with a solid DR/BC plan are: hardware, software, environment and connectivity. Utilizing Hyper-V in this capacity can help you save in the areas of software and connectivity. How it Works Hyper-V Replica works by having a primary server and a replicated server. The VM running on the primary server runs like normal, so no user knows if a server is being replicated or not. A copy of the VM is replicated to the replicated server. Once the initial copy is there, incremental updates of the changes of the primary server are copied over to the replicated server on a regular basis (every 30 seconds, 5 minutes or 15 minutes). You can also set up an extended replica server. With an extended replica server a copy of replica server is sent to another server on a regular basis (every 5 minutes or 15 minutes). Failovers There are two production level failover mechanisms: Planned Failover and an Unplanned Failover. Planned Failover A planned failover is used when you do an end-to-end validation of your recovery plan. A planned failover requires the VM to be completely shut down to ensure consistency. It is initiated from the primary VM and it moves all current data to the replica server. The VM then runs from the replica server. When done correctly, there will be minimal down time, but there is no loss of data when doing a planned failover.

2 Planned Failover is used in the following cases I want to perform host maintenance on my primary and would like to run from the replica site. My primary site is expecting some power outage I want to move over to the replica site. There s an impending typhoon I want to proactively take action to ensure business continuity. My compliance requirements mandate that every quarter, I run my workloads from the replica site for a week. Unplanned Failover An unplanned failover is used when the primary server becomes nonoperational. An unplanned failover is initiated from the replica server using the data from the last sync from the primary. It ensures that the primary machine is not running to prevent a split-brain scenario where both the primary and replica VMs are running. There will be data loss when doing an unplanned failover. Unplanned Failover is used in the following cases My primary site is experiencing unexpected power outage or a natural disaster My primary host experienced a hardware malfunction My primary site/vm has had a virus attack and I want to restore my business quickly with minimal data loss by restoring my replica VM Demonstration of Planned Failover Today I will demonstrate a planned failover of the web server for West Point Public Schools. But first, following is an overview of the West Point virtual environment. West Point Beemer ESU 2 5 minutes 15 minutes Primary Replica Extended Replica There are 11 VMs on the West Point server that are replicated to the Beemer server. There are also 4 VMs on the Beemer server replicated to the West Point server. Then all 15 VMs are replicated to the ESU 2 server. In the event that I need to run West Point servers from Beemer, I can initiate a planned failover and the data flows over the local network and the users and the public will not know that the physical host server was changed.

3 Overview of Planned Failover Process 1. With Extended Replication configured, this is the current layout West Point Beemer ESU 2 On 5 minutes Off 15 minutes Off Primary Replica Extended Replica 2. Move the Primary server to original Replica server, and continue replication to the Extended Replica server. West Point Beemer ESU 2 Off 5 minutes On 15 minutes Off Primary (but not replicating) Primary 3. To move back to the original configuration, remove all replication from all servers. Replica West Point Beemer ESU 2 Off 5 minutes 15 minutes On Off No replication No replication No replication 4. Enable replication from original replica server to original primary server. West Point Beemer ESU 2 Off 5 minutes 15 minutes On Off Replica Primary No replication 5. Perform a Planned Failover but this time enable Reverse Replication West Point Beemer ESU 2 5 minutes 15 minutes Primary Replica No Replication 6. Extend Replication from Replica server to Extended Replica server. West Point Beemer ESU 2 5 minutes 15 minutes Primary Replica Extended Replica

4 Steps to initiate a Planned Failover 1. Access VMs by using Hyper-V Manager 2. Select the server to perform the failover by clicking once on the server 3. Shut down the selected virtual machine. (While you can initiate a shut down through Hyper-V, I recommend you Connect to the VM and perform a shut down through the guest OS.) 4. Click on Replication (on the right-side) 5. Click Planned Failover 6. Click Fail Over. (Do not check Reverse the replication direction after failover if you have an Extended Replication environment)

5 7. Wait for failover process to complete. This window will disappear once the failover process completes. 8. Now the VM on the primary server is currently off

6 9. Changing to the replica server (BES), you ll see that the VM is now running Notes about a Planned Failover If you have an Extended Replica system configured, you cannot use the Reverse Replication functionality o Reverse Replication is the process where the roles of the primary and replica servers are swapped. o Reverse Replication allows the replication process to continue during a Planned Failover. If you have an Extended Replica system configured, the extended replication functionality is paused during a Planned Failover, but can be manually re-enabled during the failover.

7 To Return to the Original Replicated State 1. Remove all current replication a. Go to the original primary server and Remove Replication from the VM you want to move back. b. Since West Point has an Extended Replica server, we need to complete the extended replication setup. Switch back to the Extended Replica server and remove the replication previously configured there.

8 c. Click Remove Replication d. Verify that replication has been removed. e. Switch to the Replica server (where the VM is currently running) f. Remove the replication of the VM

9 g. Observe that the Replication is now viewed as Not Applicable 2. Set up replication. a. On the server that the VM is currently running, click Enable Replication

10 b. Click Next c. Enter the name of the Replica server. This will be the original primary server name. Click Next. d. Use certificate-based authentication (HTTPS) and ensure the box is checked for Compress the data that is transmitted over the network. Click Next.

11 e. Select the VHDs you want to replicate. Normally there is just one unless the VM includes multiple VHDs. Click Next. f. Choose the frequency at which changes will be sent to the Replica Server. I use 5 minutes (the default) to go from the primary to the replica servers. g. Choose if you want to maintain only one or more recovery points. I only keep the latest recovery point for hard drive space considerations. Click Next.

12 h. Use an existing virtual machine on the Replica server as the initial copy. Click Next. i. Click Finish j. Let the replication complete. 3. Initiate a Planned Failover a. Shut down the VM. b. Click Planned Failover c. Check the box Reverse the replication direction after failover. Click Fail Over d. Wait for the failover process to complete. e. Once complete, click Close.

13 4. Verify that the server is now running from the original server. 5. Extend Replication a. Switch to the Replica server. Select the server and select Extend Replication

14 b. Click Next. c. Enter the name of the extended replica server. Click Next. d. Use certificate-based authentication (HTTPS) and ensure the box is checked for Compress the data that is transmitted over the network. Click Next.

15 e. Choose the frequency at which changes will be sent to the Replica Server. I use 15 minutes to go from the replica server to the extended replica server. f. Choose if you want to maintain only one or more recovery points. I only keep the latest recovery point for hard drive space considerations. Click Next. g. Use an existing virtual machine on the Replica server as the initial copy.

16 h. Click Finish. i. Wait for the Extending Replication wizard to complete 6. Verify that the replication is being sent