Image Template¶
This page describes how to define a new image template. An image template follows the same syntax as the VM template.
Warning
There are some template attributes that can compromise the security of the system or the security of other VMs, and can be used only by users in the oneadmin group. These attributes can be configured in oned.conf, the default ones are labeled with *
in the following tables. See the complete list in the Restricted Attributes section.
Template Attributes¶
The following attributes can be defined in the template:
Attribute |
KVM |
vCenter |
Value |
Description |
---|---|---|---|---|
|
Mandatory |
Mandatory |
Any string |
Name that the Image will get. Every image must have a unique name. |
|
Optional |
Optional |
Any string |
Human readable description of the image for other users. |
|
Optional |
Optional |
|
Type of the image, explained in detail in the following section. If omitted, the default value is the one defined in oned.conf (install default is OS) |
|
Optional |
Optional |
|
Persistence of the image. If omitted, the default value is |
PERSISTENT_TYPE |
Optional
|
-
|
IMMUTABLE , SHAREABLE |
IMMUTABLE - An special persistent image, that will not be modified.SHAREABLE - Persistent image shareable by multiple VMs. Requires raw image FORMAT and shared datastore. Virtualization driver needs SUPPORT_SHAREABLE = "yes" This attribute should only be used for special storage configurations.
|
|
Optional |
Optional |
Any string e.g |
Prefix for the emulated device this image will be mounted at. For instance, |
|
Optional |
- |
Any string |
Target for the emulated device this image will be mounted at. For instance, |
|
Optional |
- |
|
Format of the image backing file. |
|
Optional |
- |
File system name (e.g ext4, xfs, …) |
Specific file system type. It is used for formatting datablocks and volatile disks. |
|
Mandatory (if no SOURCE) |
Mandatory (if no SOURCE) |
Any string |
Path to the original file that will be copied to the image repository. If not specified for a |
|
Mandatory (if no PATH) |
Mandatory (if no PATH) |
Any string |
Source to be used in the DISK attribute. Useful for not file-based images. |
|
Optional |
Optional |
For KVM: |
This is the type of the supporting media for the image: a block device ( |
VCENTER_DISK_TYPE |
-
|
Optional
|
vCenter: (careful with the case): delta, eagerZeroedThick, flatMonolithic, preallocated, raw, rdm, rdmp, seSparse, sparse2Gb, sparseMonolithic, thick, thick2Gb, thin
|
The type of disk has implications on performance and occupied space. Values (careful with the case): delta, eagerZeroedThick, flatMonolithic, preallocated, raw, rdm, rdmp, seSparse, sparse2Gb, sparseMonolithic, thick, thick2Gb, thin.
More information in the VMware documentation.
|
|
- |
Optional |
vCenter: Possible values (careful with the case): |
Type of controller to be used with this disk. More information in the VMware documentation |
|
Optional |
- |
|
This attribute should only be used for special storage configurations. It sets how the image is going to be exposed to the hypervisor. Images of type |
|
Optional |
Optional |
An MD5 hash |
MD5 hash to check for image integrity. |
|
Optional |
Optional |
An SHA1 hash |
SHA1 hash to check for image integrity. |
|
Optional |
Optional |
UUID value |
This attribute needs to be set for LUKS-encrypted images. Its value is UUID registered on hypervisor nodes as an identifier for the LUKS secret. |
|
- |
Optional |
|
vCenter: This attribute is set to |
Warning
Be careful when PATH
points to a compressed bz2 image, since although it will work, OpenNebula will not calculate its size correctly.
Important
All the above KVM attributes apply to Firecracker and LXC. With the exception of DEV_PREFIX
which is always virtio
for Firecracker and doesn’t apply for LXC. And TARGET
doesn’t apply to neither of them.
Mandatory attributes for DATABLOCK
images with no PATH
set:
Attribute |
Value |
Description |
---|---|---|
|
An integer |
Size in MB. |
Template Examples¶
Example of an OS
image:
NAME = "Ubuntu Web Development"
PATH = /home/one_user/images/ubuntu_desktop.img
DESCRIPTION = "Ubuntu 10.04 desktop for Web Development students.
Contains the pdf lessons and exercises as well as all the necessary
programming tools and testing frameworks."
Example of a CDROM
image:
NAME = "MATLAB install CD"
TYPE = CDROM
PATH = /home/one_user/images/matlab.iso
DESCRIPTION = "Contains the MATLAB installation files. Mount it to install MATLAB on new OS images."
Example of a DATABLOCK
image:
NAME = "Experiment results"
TYPE = DATABLOCK
# No PATH set, this image will start as a new empty disk
SIZE = 3.08
DESCRIPTION = "Storage for my Thesis experiments."
Restricted Attributes¶
All the default restricted attributes to users in the oneadmin group are summarized in the following list:
SOURCE
VCENTER_IMPORTED
These attributes can be configured in oned.conf.