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Image properties

Images can have associated properties, which are key value pairs giving additional information about the image such as what operating system is in the image or which hypervisor type is best suited to run it.

Properties available

Some of these are marked as CERN specific ones. Others are listed here as they have been fully tested on the CERN cloud infrastructure. A full list of the OpenStack image properties is available in the OpenStack documentation although some options may not have been tested or configured in the CERN cloud.

These settings are made for all the centrally provided images for the CERN cloud. User supplied images or images from other sources may not provide all of the values.

Property Setting
hw_cpu_max_sockets This allows to set the maximun number of sockets exposed to the operating system. This setting is really useful if the operating system only allows a fixed number of sockets due to licensing like Windows Desktops. For example if you set this value to 2 and you select a flavor with 4 vCPUs, the instance will have 2 sockets of 2 cores each.
  • hw_watchdog_action=reset will cause the VM to be rebooted if it does not regularly reset the watchdog timer. For more information see ithe chapter on availability techniques
  • hw_watchdog_action=disabled will not enable the watchdog. This is the default
os Which family of operating systems is this image running
  • Windows
LanDB 'Operating System' field will be updated with this value if defined.
os_version The version of the operating system. LanDB 'Operating System Version' field will be updated with this value if defined.
os_distro os_distro=CC is for CERN CentOS 7 and CentOS 8
The other settings are as per the OpenStack documentation such as Windows or rhel
os_distro_major The major distribution release number. Thus for CentOS 8.3, this would be set to 8. For Windows releases,
  • 2008 is Windows Server 2008
  • 2012 is Windows Server 2012
  • 7 is Windows 7
  • 8 is Windows 8
os_distro_minor The minor distribution release number. Thus for CentOS 8.3, this would be set to 3.
os_edition For Windows images,
  • Server means the image is a Windows Server relesae
  • Desktop is for the desktop OSes such as Windows 7
  • CERN Server means the customised version of the Server image including standard CERN components such as AFS
architecture The architecture needed to run the image.
  • x86_64 is 64 bit
  • i686 is 32 bit
release_date The date when the image was made available for production. This is in the format YYYY-MM-DDTHH:MM:SS. It is different from the updated_at field in the image which is updated when a new version is provided to the image service.
upstream_provider The URL to support provider.
  • for email links
  • for website links

Using properties

Properties can be used to automatically select images based on criteria in scripts. For example

$ openstack image list --property os_distro=CS --property os_distro_major=8 --property architecture=x86_64  --sort updated_at
| ID                                   | Name                      | Status |
| cc526ba5-37db-4e2c-9497-2044f3b71e5d | CS8 - x86_64 [2021-11-01] | active |


'os' and 'os_version' if not explicitly defined will default to 'UNKNOWN' in lanDB. Only lanDB registered values are allowed. 'Operating System' and 'Operating System Version' in lanDB can also be manipulated using instance metadata.

Last update: November 30, 2021