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Overview

Image properties are key-value metadata attached to images that influence how the compute service launches instances from that image. Properties communicate the OS type to the hypervisor, set minimum hardware requirements, configure boot firmware, and define the virtual hardware model. Well-configured properties improve compatibility and prevent launch failures from under-resourced flavors.
Prerequisites
  • An active Xloud account with appropriate permissions
  • Access to the Xloud Dashboard (https://connect.<your-domain>) or CLI configured with credentials
  • API credentials sourced (source admin-openrc.sh)

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Essential Properties Reference

Property KeyExample ValuePurpose
os_typelinuxInforms the hypervisor of the guest OS family
os_distroubuntuOS distribution for XAVS Guest Agent configuration
os_version24.04OS version string
hw_machine_typeq35Sets the emulated chipset (q35 for UEFI, i440fx for legacy BIOS)
hw_firmware_typeuefiBoot firmware — uefi or bios
hw_disk_busvirtioDisk controller — virtio (best performance) or ide
hw_scsi_modelvirtio-scsiSCSI controller model when hw_disk_bus=scsi
hw_vif_modelvirtioNetwork interface model
hw_tpm_modeltpm-crbEnable virtual TPM device (requires platform support)

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Set Properties

Open image details

Navigate to Project → Compute → Images and click the image name.

Edit properties

Click Edit Image. In the Metadata section, add key-value pairs using the property keys from the reference table above.

Save changes

Click Update Image to apply the properties.
Properties are saved and immediately active for new instance launches.

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Hardware Configuration Examples

Modern Linux with UEFI boot

Ubuntu 24.04 / RHEL 9 UEFI configuration
openstack image set \
  --property hw_firmware_type=uefi \
  --property hw_machine_type=q35 \
  --property hw_disk_bus=virtio \
  --property hw_vif_model=virtio \
  --property os_type=linux \
  ubuntu-24.04-lts
Windows Server 2022 configuration
openstack image set \
  --property hw_firmware_type=uefi \
  --property hw_machine_type=q35 \
  --property hw_disk_bus=virtio \
  --property hw_vif_model=virtio \
  --property os_type=windows \
  --property os_distro=windows \
  --property os_version=2022 \
  windows-server-2022
Windows instances require VirtIO drivers installed in the guest before setting hw_disk_bus=virtio. Without drivers, Windows will fail to boot from a VirtIO disk.
Legacy BIOS configuration for older OS images
openstack image set \
  --property hw_firmware_type=bios \
  --property hw_machine_type=i440fx \
  --property hw_disk_bus=ide \
  legacy-centos7

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Image Metadata & Tags

Beyond hardware properties, images support two additional metadata mechanisms: arbitrary key-value properties for any custom annotation, and tags — simple string labels for filtering and searching across the image catalog.

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Arbitrary Properties

Any --property key=value pair is valid. Properties not recognized by the hypervisor are stored and returned but have no behavioral effect. Use them for operational metadata:
Set operational metadata properties
openstack image set \
  --property os_lifecycle=lts \
  --property os_support_until=2029-04-30 \
  --property xloud_base_image=true \
  --property os_security_patch_date=2026-03-01 \
  --property data_classification=public \
  --property compliance=pci-dss \
  ubuntu-24.04-lts
Custom Property KeyExample ValuePurpose
os_lifecyclelts, standard, eolOS support status
os_support_until2029-04-30End-of-support date for filtering
xloud_base_imagetrueMarks Xloud-maintained base images
os_security_patch_date2026-03-01Last security patch applied
data_classificationpublic, confidentialData handling tag
compliancepci-dss, hipaa, iso27001Regulatory compliance designation
build_version20260301-001CI/CD build identifier
min_kernel_version5.15Minimum kernel required by the OS

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Image Tags

Tags are plain string labels — no key, just a value. They enable fast catalog filtering in the Dashboard and CLI without requiring exact property key lookups.

Edit the image

Navigate to Project → Compute → Images, click the image name → Edit Image.

Add tags

In the Edit Image dialog, locate the Tags field. Type a tag and press Enter to add it. Add multiple tags.Useful tags: ubuntu, lts, production-ready, gpu-compatible, windows, pci-dss, baseline-2026, no-cloud-init

Save

Click Update Image. Tags are immediately searchable in the image list.

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Tags vs Properties

FeatureTagsProperties
FormatSimple strings (no key)Key-value pairs
Use forCatalog filtering, search, groupingHypervisor hints, operational metadata
Filteringopenstack image list --tag <tag>openstack image list --property key=value
Hypervisor-awareNeverSome keys are (hw_*, os_*)

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Remove Properties

Remove a specific property
openstack image unset \
  --property hw_tpm_model \
  ubuntu-24.04-lts

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Next Steps

Image Formats

Choose the right disk format to match your property configuration.

Upload an Image

Upload images and set properties at upload time using CLI flags.

Image Admin Guide — Metadata

Define structured metadata namespaces for consistent property schemas.

Troubleshooting

Resolve launch failures caused by incorrect image property values.