# Unified Limits Quotas

Since the Nova 28.0.0 (2023.2 Bobcat) release, it is recommended to use Keystone unified limits for Nova quota limits.

For information about legacy quota limits, see the legacy quota documentation.

Nova uses a quota system for setting limits on resources such as number of instances or amount of CPU that a specific project or user can use.

Quota limits are set by admin and retrieved for enforcement using the Keystone API.

## Types of quota

Unified limit resource names for resources that are tracked as resource classes in the placement service follow the naming pattern of the `class:` prefix followed by the name of the resource class. For example: class:VCPU, class:PCPU, class:MEMORY_MB, class:DISK_GB, class:VGPU.

Quota name | Description
--- | ---
class:VCPU | Number of shared CPU cores (VCPUs) allowed per project.
class:PCPU | Number of dedicated CPU cores (PCPUs) allowed per project.
servers | Number of instances allowed per project.
server_key_pairs | Number of key pairs allowed per user.
server_metadata_items | Number of metadata items allowed per instance.
class:MEMORY_MB | Megabytes of instance ram allowed per project.
server_groups | Number of server groups per project.
server_group_members | Number of servers per server group.
class:DISK_GB | Gigabytes of instance disk allowed per project.
class:<any resource class in the placement service> | Any resource class in the placement service that is allocated by Nova can have a quota limit specified for it. Example: class:VGPU.

The following quotas were previously available but were removed in microversion 2.36 as they proxied information available from the networking service.

Quota name | Description
--- | ---
fixed_ips | Number of fixed IP addresses allowed per project. This number must be equal to or greater than the number of allowed instances.
floating_ips | Number of floating IP addresses allowed per project.
networks | Number of networks allowed per project (no longer used).
security_groups | Number of security groups per project.
security_group_rules | Number of security group rules per project.

Similarly, the following quotas were previously available but were removed in microversion 2.57 as the personality files feature was deprecated.

Quota name | Description
--- | ---
injected_files | Number of injected files allowed per project.
injected_file_content_bytes | Number of content bytes allowed per injected file.
injected_file_path_bytes | Length of injected file path.

## Usage

### Project quotas

To list all default quotas for projects, run:

    $ openstack registered limit list

Note

This lists default quotas for all services and not just nova.

For example:

    $ openstack registered limit list
    +----------------------------------+----------------------------------+------------------------------------+---------------+-------------+-----------+
    | ID                               | Service ID                       | Resource Name                      | Default Limit | Description | Region ID |
    +----------------------------------+----------------------------------+------------------------------------+---------------+-------------+-----------+
    | eeee406035fc4a7892c6fc6fcc76e61a | b5d97619e6354c03be50c6b1589e6547 | image_size_total                   |          1000 | None        | RegionOne |
    | b99d35b1b7b74cd0a26a6311963328af | b5d97619e6354c03be50c6b1589e6547 | image_stage_total                  |          1000 | None        | RegionOne |
    | 70945789dad24082bc2a8cdbf53a5091 | b5d97619e6354c03be50c6b1589e6547 | image_count_total                  |           100 | None        | RegionOne |
    | 908d86c0ac3f46d0bb45ed9194710ea7 | b5d97619e6354c03be50c6b1589e6547 | image_count_uploading              |           100 | None        | RegionOne |
    | be6dfeebb7c340e8b93b602d41fbff9b | 8b22bf8a66fa4524a522b2a21865bbf2 | servers                            |            10 | None        | None      |
    | 8a658096236549788e61f4fcbd5a4a12 | 8b22bf8a66fa4524a522b2a21865bbf2 | class:VCPU                         |            20 | None        | None      |
    | 63890db7d6a14401ba55e7f7022b95d0 | 8b22bf8a66fa4524a522b2a21865bbf2 | class:MEMORY_MB                    |         51200 | None        | None      |
    | 221ba1c19d2c4272952663828d659013 | 8b22bf8a66fa4524a522b2a21865bbf2 | server_metadata_items              |           128 | None        | None      |
    | 8e61cabd2e854a11bdd2cf94efd702d1 | 8b22bf8a66fa4524a522b2a21865bbf2 | server_injected_files              |             5 | None        | None      |
    | 3d259390f70e4e9b88ecb2b0fa075f9b | 8b22bf8a66fa4524a522b2a21865bbf2 | server_injected_file_content_bytes |         10240 | None        | None      |
    | a12e10b991cc4bdd8e6ff30f6e6c15ac | 8b22bf8a66fa4524a522b2a21865bbf2 | server_injected_file_path_bytes    |           255 | None        | None      |
    | a32a9080be6b4a5481c16a91fe329e6f | 8b22bf8a66fa4524a522b2a21865bbf2 | server_key_pairs                   |           100 | None        | None      |
    | 86408bb7a0e542b18404ec7d348da820 | 8b22bf8a66fa4524a522b2a21865bbf2 | server_groups                      |            10 | None        | None      |
    | 17c4552c5aad4afca4813f37530fc897 | 8b22bf8a66fa4524a522b2a21865bbf2 | server_group_members               |            10 | None        | None      |
    +----------------------------------+----------------------------------+------------------------------------+---------------+-------------+-----------+

To show details about a default limit, run:

    $ openstack registered limit show <registered-limit-id>

For example:

    $ openstack registered limit show 8a658096236549788e61f4fcbd5a4a12
    +---------------+----------------------------------+
    | Field         | Value                            |
    +---------------+----------------------------------+
    | default_limit | 20                               |
    | description   | None                             |
    | id            | 8a658096236549788e61f4fcbd5a4a12 |
    | region_id     | None                             |
    | resource_name | class:VCPU                       |
    | service_id    | 8b22bf8a66fa4524a522b2a21865bbf2 |
    +---------------+----------------------------------+

To list the currently set quota values for your project, run:

    $ openstack limit list

For example:

    $ openstack limit list
    +----------------------------------+----------------------------------+----------------------------------+---------------+----------------+-------------+-----------+
    | ID                               | Project ID                       | Service ID                       | Resource Name | Resource Limit | Description | Region ID |
    +----------------------------------+----------------------------------+----------------------------------+---------------+----------------+-------------+-----------+
    | 8b3364b2241e4090aaaa49355c7a5b56 | 5cd3281595a9497ba87209701cd9f3f2 | 8b22bf8a66fa4524a522b2a21865bbf2 | class:VCPU    |              5 | None        | None      |
    +----------------------------------+----------------------------------+----------------------------------+---------------+----------------+-------------+-----------+

To show details about a quota limimt, run:

    $ openstack limit show <limit-id>

For example:

    $ openstack limit show 8b3364b2241e4090aaaa49355c7a5b56
    +----------------+----------------------------------+
    | Field          | Value                            |
    +----------------+----------------------------------+
    | description    | None                             |
    | domain_id      | None                             |
    | id             | 8b3364b2241e4090aaaa49355c7a5b56 |
    | project_id     | 5cd3281595a9497ba87209701cd9f3f2 |
    | region_id      | None                             |
    | resource_limit | 5                                |
    | resource_name  | class:VCPU                       |
    | service_id     | 8b22bf8a66fa4524a522b2a21865bbf2 |
    +----------------+----------------------------------+

this page last updated: 2026-06-10 20:05:07

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