Capture requirements

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This topic describes the support and requirements for capturing a virtual machine in your IBM Power Virtualization Center environment.

Sources that you can capture

You can create an image by capturing a virtual machine that is running any of the operating systems that are supported by PowerVC, as described in the hardware and software requirements.

Requirements

Before you can capture a virtual machine, you should ensure that the following requirements are met:

  • Your PowerVC environment is configured as described in setting up the PowerVC environment.
  • The host that the virtual machine resides on is registered in PowerVC.
  • The virtual machine uses virtual I/O and virtual storage.
  • Operating systems that use LILO or Yaboot boot loaders such as SLES 10, SLES 11, Red Hat® Enterprise Linux® (RHEL) 5, and RHEL 6 have special considerations when using virtual machines that have multiple disks. Follow the instructions in Configuring the Linux boot loader.
  • For SLES 12 operating systems, if you are deploying with a network configuration that has a static IP as the primary adapter and DHCP as secondary adapters, edit the following property in the virtual machine. Otherwise, the DHCP adapters might override the default gateway of the primary (static) adapter. In /etc/sysconfig/network/dhcp, change DHCLIENT_SET_DEFAULT_ROUTE = "yes" to DHCLIENT_SET_DEFAULT_ROUTE = "no".
  • If you want your Linux virtual machine to have multiple paths to storage (MPIO), you must configure Linux for MPIO on the root device before capturing the virtual machine.
    Tip: The default Red Hat Enterprise Linux configuration creates a restrictive blacklist for all WWPN entries. This list must be removed to enable deployment of a captured image. The configuration is described in the following Red Hat Enterprise Linux document: Using Device-Mapper Multipath: Chapter 4.2 Configuration File Blacklist
  • The virtual machine is powered off. When you power off a virtual machine, the status will appear as Active until the virtual machine has completely shut down. You can select the virtual machine for capture while the status is still displayed as Active.
  • PowerVC allows a virtual machine to have more than 128 volumes when using initiator port groups in the storage connectivity group. Capturing a virtual machine with more than 256 volumes requires the below configuration changes to be performed.
    • In the file /etc/nova/nova.conf under the quota section, add or update the conf property metadata_items to N.
    • In the file /etc/glance/glance-api.conf under the DEFAULT section, set the value of image_property_quota to >= N+200.
    • Restart nova and glance services using the powervc-services command.

    Capturing N number of volumes also requires the back-end storage to support N parallel copy or clone operations.

Image activation considerations

Consider the following when using image activation technology:

  • On AIX®, when using a version of cloud-init that PowerVC does not support, set ghostdev to 1 before capture. After capture, reboot the captured virtual machine and set ghostdev to 0.