Microsoft Azure recently announced the support for large disks up to 4 TB. Now Azure Site Recovery supports protecting on-premises VMs and physical servers with disks up to 4095 GB in size to Azure. Many customers use disks with more than 1 TB in capacity for various reasons. A good example would be SQL databases and file servers. The availability of large disks in Azure allows you to leverage ASR as a DR solution for your datacenter infrastructure.
Large disks in Azure are available both in standard and premium tiers. Standard disks offer two sizes S40 (2TB) and S50 (4TB) for both managed and unmanaged disks. If you have IO intensive workloads that require premium storage you can use P40 (2TB) and P50 (4TB) for both managed and unmanaged disks.
Pre-requisites for protecting VMs with large disks in ASR
You need to make sure that your on-premises ASR infrastructure components are up-to-date before you you start protecting VMs and/or physical servers with disks greater than 1 TB in size.
||Install the latest update on the Configuration server, additional process servers, additional master target servers and agents.
|SCVMM managed Hyper-V environments
||Install the latest Microsoft Azure Site Recovery Provider update on the on-premises VMM server.
|Standalone Hyper-V servers not managed by SCVMM
||Install the latest Microsoft Azure Site Recovery Provider on each Hyper-V server that is registered with Azure Site Recovery.
Note that protecting Azure VMs with large disks is not a currently supported scenario.
Microsoft has recently announced a preview for protecting Azure IaaS VMs with ASR. Now you can protect Azure VMs running Windows Server 2016 . Also ASR now supports protecting Azure IaaS VMs with Storage Spaces. Storage Spaces allow you to improve IO performance by striping disks and to create logical disks larger than 4 TB.
Following is a list of all supported OS versions that can be protected using ASR.
- Windows Server 2016 (Server Core and Server with Desktop Experience)
- Windows Server 2012 R2
- Windows Server 2012
- Windows Server 2008 R2 SP1 and above
- Red Hat Enterprise Linux 6.7, 6.8, 7.0, 7.1, 7.2, 7.3
- CentOS 6.5, 6.6, 6.7, 6.8, 7.0, 7.1, 7.2, 7.3
- Ubuntu 14.04/16.04 LTS Server (only supported kernel versions)
- SUSE Linux Enterprise Server 11 SP3
- Oracle Enterprise Linux 6.4, 6.5 running either the Red Hat compatible kernel or Unbreakable Enterprise Kernel Release 3 (UEK3)
Azure Site Recovery team has made some significant improvements to the service during past couple of months. Recently Microsoft has announced the support for managed disks and availability sets with ASR.
Managed Disks in ASR
Managed disks allow simplified disk management for Azure IaaS VMs and users no longer have to leverage storage accounts to store the VHD files. With ASR, you can attach managed disks to your IaaS VMs during a failover or migration to Azure. Additional using managed disks ensure reliability for VMs placed in Availability Sets by guaranteeing that the failed over VMs are automatically placed in different storage scale units (stamps) to avoid any single point of failure.
Availability Sets in ASR
Site Recovery now supports configuring VMs into availability sets in ASR VM settings. Previously users had to leverage a script that can be integrated to the recovery plan to achieve this goal. Now you can configure availability sets before the failover so that you do not need to rely on any manual intervention.
Below are some considerations to be made when you are using these two features.
- Managed disks are supported only in Resource manager deployment model.
- VMs with managed disks can only be part of availability sets with “Use managed disks” property set to “Yes“.
- Creation of managed disks will fail , if the replication storage account was encrypted with Storage Service Encryption (SSE). If this happens during a failover you can either set “Use managed disks” to “No” in the Compute and Network settings for the VM and retry failover or disable protection for the vm and protect it to a storage account without Storage service encryption enabled.
- Use this option only if you plan to migrate to Azure for any SCVMM managed/unmanaged Hyper-V VM’s Failback from Azure to on-premises Hyper-V environment is not currently supported for VMs with managed disks.
- Disaster Recovery of Azure IaaS machines with managed disks is not supported currently.
Business Continuity & Disaster Recovery is a critical functionality in today’s IT business. Microsoft Azure Site Recovery is premier solution that can reduce your BCDR cost drastically. Planing a DR solution requires lot of effort and time and using Azure Site Recovery enterprises can have a bullet proof BCDR solution within couple of days where you only pay when a disaster has actually happened.
In Savision’s newest free whitepaper MVP Peter de Tender explains why you should focus on building an effective Disaster Recovery Plan for your virtualized Data center. This whitepaper explains,
- How to leverage Microsoft Azure Site Recovery to build a DR solution for Hyper-V?
- Azure Site Recovery for VMWare & Physical servers
- Leveraging Azure IaaS for a hybrid data center,
You can download the whitepaper from here.
Azure Site recovery is a great cost effective platform to host your DR sites. These days most of my time is spent on this technology and I’m experimenting on new things everyday. Troubleshooting ASR is not so easy as the information available is relatively low in some cases.
In one of my ASR deployments I have noticed below issue.
As per Microsoft Documentation for a SCVMM to ASR scenario we can enable the protected VM in ASR to have a predefined IP address from a mapped virtual network. The guidelines read as “If the network adapter of source virtual machine is configured to use static IP then the user can provide the IP for the target virtual machine. User can use this capability to retain the ip of the source virtual machine after a failover. If no IP is provided any available IP would be given to network adapter at the time of failover. In case the target IP provided by user is already used by some other virtual machine that is already running in Azure then the failover would fail.”
Now I have enabled replication on one VM and checked the configuration section and guess what the only option available was DHCP.
ASR sees what VMM can see. In this case the on premise logical network didn’t have any static IP pool assigned to it. When I checked the VM properties in VMM I noticed it is also reflecting IP as DHCP.
Below are the steps I’ve performed to overcome this issue.
- Create a static IP Pool for my logical network. As I didn’t use network virtualization I didn’t need to create a static IP pool for my VM network. You can follow this guide to create a static IP pool in a logical network.
- This static IP pool should be of the same range that you used for your VMs. If you click the Connection details button as in above screen you get get the actual IP address assigned in the OS level and determine the range.
- Next step is to refresh virtual machines. Once you refresh a VM and and check the Network adapter properties in SCVMM it will now display the IP as static.
- I have already replicated one VM. For that I had to disconnect it from the on-premise network (Connectivity > Not Connected in above screen) and connect it again to the same VM network. Then I did a VM refresh and et viola now I can see the static IP option in the ASR portal.