[ aws . ec2 ]



Modifies a Capacity Reservation’s capacity and the conditions under which it is to be released. You cannot change a Capacity Reservation’s instance type, EBS optimization, instance store settings, platform, Availability Zone, or instance eligibility. If you need to modify any of these attributes, we recommend that you cancel the Capacity Reservation, and then create a new one with the required attributes.

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.


--capacity-reservation-id <value>
[--instance-count <value>]
[--end-date <value>]
[--end-date-type <value>]
[--accept | --no-accept]
[--dry-run | --no-dry-run]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]


--capacity-reservation-id (string)

The ID of the Capacity Reservation.

--instance-count (integer)

The number of instances for which to reserve capacity.

--end-date (timestamp)

The date and time at which the Capacity Reservation expires. When a Capacity Reservation expires, the reserved capacity is released and you can no longer launch instances into it. The Capacity Reservation’s state changes to expired when it reaches its end date and time.

The Capacity Reservation is cancelled within an hour from the specified time. For example, if you specify 5/31/2019, 13:30:55, the Capacity Reservation is guaranteed to end between 13:30:55 and 14:30:55 on 5/31/2019.

You must provide an EndDate value if EndDateType is limited . Omit EndDate if EndDateType is unlimited .

--end-date-type (string)

Indicates the way in which the Capacity Reservation ends. A Capacity Reservation can have one of the following end types:

  • unlimited - The Capacity Reservation remains active until you explicitly cancel it. Do not provide an EndDate value if EndDateType is unlimited .

  • limited - The Capacity Reservation expires automatically at a specified date and time. You must provide an EndDate value if EndDateType is limited .

Possible values:

  • unlimited

  • limited

--accept | --no-accept (boolean)

Reserved. Capacity Reservations you have created are accepted by default.

--dry-run | --no-dry-run (boolean)

Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is DryRunOperation . Otherwise, it is UnauthorizedOperation .

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.


Example 1: To change the number of instances reserved by an existing capacity reservation

The following modify-capacity-reservation example changes the number of instances for which the capacity reservation reserves capacity.

aws ec2 modify-capacity-reservation \
    --capacity-reservation-id cr-1234abcd56EXAMPLE \
    --instance-count 5


    "Return": true

Example 2: To change the end date and time for an existing capacity reservation

The following modify-capacity-reservation example modifies an existing capacity reservation to end at the specified date and time.

aws ec2 modify-capacity-reservation \
    --capacity-reservation-id cr-1234abcd56EXAMPLE \
    --end-date-type limited \
    --end-date 2019-08-31T23:59:59Z

For more information, see Modifying a Capacity Reservation in the Amazon Elastic Compute Cloud User Guide for Linux Instances.


Return -> (boolean)

Returns true if the request succeeds; otherwise, it returns an error.