Manage Flavors¶
Admin users can use the openstack flavor command to customize and manage flavors. To see information for this command, run:
$ openstack flavor --help
Command "flavor" matches:
flavor create
flavor delete
flavor list
flavor set
flavor show
flavor unset
Note
Configuration rights can be delegated to additional users by redefining
the access controls for os_compute_api:os-flavor-manage:create
,
os_compute_api:os-flavor-manage:update
and
os_compute_api:os-flavor-manage:delete
in /etc/nova/policy.yaml
on the nova-api
server.
Note
Flavor customization can be limited by the hypervisor in use. For example the libvirt driver enables quotas on CPUs available to a VM, disk tuning, bandwidth I/O, watchdog behavior, random number generator device control, and instance VIF traffic control.
For information on the flavors and flavor extra specs, refer to Flavors.
Create a flavor¶
List flavors to show the ID and name, the amount of memory, the amount of disk space for the root partition and for the ephemeral partition, the swap, and the number of virtual CPUs for each flavor:
$ openstack flavor list
To create a flavor, specify a name, ID, RAM size, disk size, and the number of vCPUs for the flavor, as follows:
$ openstack flavor create FLAVOR_NAME --id FLAVOR_ID \ --ram RAM_IN_MB --disk ROOT_DISK_IN_GB --vcpus NUMBER_OF_VCPUS
Note
Unique ID (integer or UUID) for the new flavor. If specifying ‘auto’, a UUID will be automatically generated.
Here is an example that creates a public
m1.extra_tiny
flavor that automatically gets an ID assigned, with 256 MB memory, no disk space, and one VCPU.$ openstack flavor create --public m1.extra_tiny --id auto \ --ram 256 --disk 0 --vcpus 1
If an individual user or group of users needs a custom flavor that you do not want other projects to have access to, you can create a private flavor.
$ openstack flavor create --private m1.extra_tiny --id auto \ --ram 256 --disk 0 --vcpus 1
After you create a flavor, assign it to a project by specifying the flavor name or ID and the project ID:
$ openstack flavor set --project PROJECT_ID m1.extra_tiny
For a list of optional parameters, run this command:
$ openstack help flavor create
In addition, you can set or unset properties, commonly referred to as “extra specs”, for the existing flavor. The
extra_specs
metadata keys can influence the instance directly when it is launched. If a flavor sets thequota:vif_outbound_peak=65536
extra spec, the instance’s outbound peak bandwidth I/O should be less than or equal to 512 Mbps. There are several aspects that can work for an instance including CPU limits, Disk tuning, Bandwidth I/O, Watchdog behavior, and Random-number generator. For information about available metadata keys, see Flavors.For a list of optional parameters, run this command:
$ openstack flavor set --help
Modify a flavor¶
Only the description of flavors can be modified (starting from microversion 2.55). To modify the description of a flavor, specify the flavor name or ID and a new description as follows:
$ openstack --os-compute-api-version 2.55 flavor set --description <DESCRIPTION> <FLAVOR>
Note
The only field that can be updated is the description field. Nova has historically intentionally not included an API to update a flavor because that would be confusing for instances already created with that flavor. Needing to change any other aspect of a flavor requires deleting and/or creating a new flavor.
Nova stores a serialized version of the flavor associated with an
instance record in the instance_extra
table. While nova supports
updating flavor extra_specs it does not update the embedded flavor
in existing instances. Nova does not update the embedded flavor
as the extra_specs change may invalidate the current placement
of the instance or alter the compute context that has been
created for the instance by the virt driver. For this reason
admins should avoid updating extra_specs for flavors used by
existing instances. A resize can be used to update existing
instances if required but as a resize performs a cold migration
it is not transparent to a tenant.
Delete a flavor¶
To delete a flavor, specify the flavor name or ID as follows:
$ openstack flavor delete FLAVOR
Default Flavors¶
Previous versions of nova typically deployed with default flavors. This was removed from Newton. The following table lists the default flavors for Mitaka and earlier.
Flavor |
VCPUs |
Disk (in GB) |
RAM (in MB) |
---|---|---|---|
m1.tiny |
1 |
1 |
512 |
m1.small |
1 |
20 |
2048 |
m1.medium |
2 |
40 |
4096 |
m1.large |
4 |
80 |
8192 |
m1.xlarge |
8 |
160 |
16384 |