Operating Systems Adaptations

This topic describes the changes performed by the Velostrata RPM, as well as the VM modifications made for the run-in-cloud and detach operations for both Windows VMs and Linux VMs.

Changes Performed by Velostrata RPM

The Velostrata RPM prepares the Linux machine for booting in cloud using the Velostrata solution. The package can remain installed when the VM is running in VMware on-premises/Source cloud, as changes are activated only when detecting a run-in-cloud operation. Upon removal of the package, all changes are reverted.

The set of changes made to the system are:

  • Enable boot in-cloud integration.
  • Enable serial console log integration.
  • Cloud-specific changes for the Velostrata storage channel.
  • Hardware-specific adaptations for cloud migration.

For more detailed technical information, contact Velostrata support.

 

VM Modification for Run in Cloud – Windows VM

When you move a VM to the cloud, Velostrata shuts down the VM gracefully, and takes a safe point snapshot of the VM prior to its move to the cloud.

Modifications to the networking and storage drivers are then made to allow the VM to boot in the cloud.

  • Install driver: NETKVM driver installation for GCP.
  • Change network configuration.
  • System tuning for iSCSI and MPIO access.
  • Change license/edition.
  • Disable VMware tools.
  • Change page file location.
  • Ensure hibernation is disabled.
  • Change recovery options.
  • Enable RDP.
  • Deploy Velostrata framework that allows you to run custom actions

VM Modification for Run in Cloud – Linux VM

The Velostrata RPM is required to be installed before migrating to the cloud.

When you move a VM to the cloud, Velostrata shuts down the VM gracefully (if it is running  this requires VMware Tools to be installed in the VM), and takes a safe point snapshot of the VM prior to its move to the cloud. Modifications to the networking and storage drivers are then made to allow the VM to boot in the cloud.

  • Make the necessary changes to the boot sequence in order to boot in cloud (initrd).
  • Enable serial console log integration.
  • Make changes specific to GCP as needed.
  • The following modifications are dynamically applied in the cloud:
    • Remount mounts with the _netdev option to support the proper shutdown sequence.
    • Remap swap files.
    • Start Velostrata keep-alive service.
    • Perform disk optimizations.
    • Perform network configuration adaptation including the following:
      • Remove static IPs and routes: Most migrated systems are preconfigured to static network environments, which includes pre-defined IPs, gateways, routes, network cards, etc. Cloud environments, however, only allow DHCP configuration with network topology managed outside of the VM itself. RPM contains built-in actions to remove all static configuration and reconfigure the default network interface (typically eth0) with DHCP.
      • Primary IP of hostname is updated in /etc/hosts: Some migrated applications rely on /etc/hosts to extract local IP address based on the /etc/host entry. When the VM/application is moved to cloud this involves, among other changes, change of the IP address. RPM contains built-in actions to correct /etc/hosts with the new IP address to preserve compatibility with migrated applications.

VM Modification for Detach – Windows VM

During detach of a Windows VM, Velostrata performs a cloud agent installation as recommended by GCP, via a VM agent for Windows

Note: These changes are in addition to those made for the run-in-cloud operation.

VM Modification for Detach – Linux VM

To ensure proper Linux boot and functionality after detach, the framework includes the following built-in actions for detached VMs:

  • Further tuning of the network configuration.

Note: These changes are in addition to those made for the run-in-cloud operation.