You can now start using HCX OS Assisted Migration to migrate non-vSphere workloads into a vSphere environment with HCX Enterprise. In this blog, go step by step using HCX to migrate a CentOS 6.7 Linux VM running on a RHEL KVM host.
Currently VMware customers use VMware HCX to migrate and rebalance vSphere workloads to VMware Cloud Foundation based private clouds and public clouds (such as VMware Cloud on AWS, IBM Cloud, etc.) as part of data center modernization and evacuation projects and hybrid cloud initiatives. HCX delivers live and bulk migration capabilities without requiring redesign of the application or rearchitecting of networks.
Now there’s a new data mover in HCX for migrating non-vSphere workloads (for example, applications running on RedHat OpenStack/KVM, and Microsoft Hyper-V environments) into a vSphere environment, providing customers a simple and seamless path to re-platforming application workloads. This new capability is called OS Assisted Migration (OSAM) and is available in the HCX Enterprise edition.
The current HCX Enterprise release supports the following KVM guest VM Operating Systems for migrating into a vSphere environment: RHEL 6.x (64-bit), RHEL 7.x (64-bit), CentOS 6.x (64-bit), CentOS 7.x (64-bit), Windows Server 2012, and Windows Server 2012 R2. The supported guest VM Operating System list will continue to grow with future releases.
For this example, let’s use HCX to migrate a CentOS 6.7 Linux VM running on a RHEL KVM host. The VM hostname is myapp-ws.
We deploy a minimal vSphere cluster near the source KVM environment. We then install and configure HCX software on the source and target SDDC environments. You will notice that a new OSAM Service Appliance is available when creating a service mesh in HCX. The OSAM Service appliance manifests itself as Sentinel Gateway Appliance on the source SDDC and as Sentinel Data Receiver Appliance on the destination SDDC.
The OSAM capability requires you to install Sentinel software on the non-vSphere workload that you would like to migrate to a vSphere environment. Sentinel software is available for download from the HCX Management UI.
Sentinel software requires root/Administrator access for its operation. It runs in user space and is responsible for replicating and synchronizing the server (metadata, boot and data disks that include OS, application and user data) into the target vSphere environment. You can push Sentinel software using your favorite tool (for example, Puppet, Chef, Ansible, etc.) to all the VMs that need to be migrated. I have downloaded and copied the Linux Sentinel software bundle on the KVM guest VM myapp-ws. Let’s install it.
Sentinel software on the guest VM, myapp-ws in our test, establishes a secure connection with the HCX Sentinel Gateway appliance running at the source SDDC. This registers the guest VM with HCX Manager and shows up in the inventory as a candidate for migration.
Let’s select myapp-ws for migration. We provide compute container (cluster, host, resource pool), data storage and networking information the migrated virtual machine will use at the target vSphere site.
I had also extended the myapp-ws virtual machine network from the KVM environment to the target vSphere site.
myapp-ws has two network interfaces and I have associated eth1 interface with the extended network and also selected “Retain MAC address” in the Extended Options section. The “Retain MAC address” option is required in environments where DHCP is used to assign IP addresses. This means that myapp-ws will have the same IP address as before after it’s been migrated to the vSphere environment—we don’t need to worry about any issues that arise as a result of re-IP’ing of workload. Moreover, myapp-ws server after it has been migrated to the target vSphere platform will be Layer-2 adjacent to virtual machines on the origin network in the KVM environment. As a result, it can continue to access any services that still reside in the KVM environment.
Once you are satisfied with the migration options, you ask for the migration process to start. The migration process consists of transfer and switchover. During the transfer phase, boot and data disk contents are replicated from the source system (myapp-ws VM running in a KVM environment). Sentinel software on the source VM uses Operating System facilities to replicate data. Replication traffic flows over a secure channel from the source VM to the HCX Sentinel Gateway (SGW) appliance on the source side vSphere environment. SGW simply forwards the replication traffic to the HCX Sentinel Data Receiver (SDR) appliance on the target vSphere site via the secure and optimized transport fabric created as a result of configuring a multi-site service mesh between the source and target vSphere environments. The HCX Manager allocates disks that correspond to the source VMs and attaches them to the SDR appliance. The SDR appliance writes replication data into these disks.
The source system myapp-ws remains online during the transfer phase and continues to provide service. There is no interruption. Once the initial sync completes, the switchover process starts unless it’s scheduled to start during a maintenance window. If the initial sync completes before the start of the scheduled switchover window, it enters a continual sync phase where it continues to do delta syncs. During the switchover phase, the source system myapp-ws is quiesced prior to final delta sync to have a coherent replica of the source system. A fix-up process then performs hardware-mapping and guest OS software stack modification (including driver injection and installation of VMware tools) to make the system runnable in the vSphere environment. These modifications are performed on the replica disks, source VM is not modified. Finally, the source system myapp-ws is powered off and the migrated VM myapp-ws on the target vSphere environment is powered on.
myapp-ws server is now running in the target vSphere environment. It has been successfully migrated from the KVM environment to the target vSphere environment. It’s that simple!
Summary
You can now start using HCX OS Assisted Migration to migrate non-vSphere workloads into a vSphere environment with HCX Enterprise. To learn more and hear what other customers are saying, visit https://cloud.vmware.com/vmware-hcx and join us for VMworld Session CNET2141BU, “HCX: Automating Workload Migration for Data Centers and Clouds.” Join the conversation @VMwareHCX.
