# Monitor the progress of Amazon EBS volume modifications
<a name="monitoring-volume-modifications"></a>

When you modify an EBS volume, it goes through a sequence of states. The volume enters the `modifying` state, the `optimizing` state, and finally the `completed` state. At this point, the volume is ready to be further modified. 

While the volume is in the `optimizing` state, your volume performance is in between the source and target configuration specifications. Transitional volume performance will be no less than the source volume performance. If you are downgrading IOPS, transitional volume performance is no less than the target volume performance.

Volume modification changes take effect as follows:
+ Size increases take effect once the volume modification reaches the `optimizing` state, which usually takes a few seconds.
+ Performance (IOPS and throughput) changes can take from a few minutes to a few hours to complete, depending on the requested volume configuration. Typically, a fully used 1-TiB volume can take about 6 hours to migrate to a new performance configuration. In some cases, it can take more than 24 hours for a new performance configuration to take effect, such as when the volume has not been fully initialized.

The possible volume states are `creating`, `available`, `in-use`, `deleting`, `deleted`, and `error`.

The possible modification states are `modifying`, `optimizing`, and `completed`.

------
#### [ Console ]

**To monitor progress of a modification**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Volumes**.

1. Select the volume.

1. The **Volume state** column and the **Volume state** field in the **Details** tab contain information in the following format: *Volume state* - *Modification state* (*Modification progress*%). The following image shows the volume and volume modification states.  
![\[Volume and volume modification states\]](http://docs.aws.amazon.com/ebs/latest/userguide/images/volume_state.png)

   After the modification completes, only the volume state is displayed. The modification state and progress are no longer displayed.

   Alternatively, you can use Amazon EventBridge to create a notification rule for volume modification events. For more information, see [Getting started with Amazon EventBridge](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-get-started.html).

------
#### [ AWS CLI ]

**To monitor progress of a modification**  
Use the [describe-volumes-modifications](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-volumes-modifications.html) command to view the progress of one or more volume modifications. The following example describes the volume modifications for two volumes.

```
aws ec2 describe-volumes-modifications \
    --volume-ids vol-11111111111111111 vol-22222222222222222
```

In the following example output, the volume modifications are still in the `modifying` state. Progress is reported as a percentage.

```
{
    "VolumesModifications": [
        {
            "TargetSize": 200,
            "TargetVolumeType": "io1",
            "ModificationState": "modifying",
            "VolumeId": "vol-11111111111111111",
            "TargetIops": 10000,
            "StartTime": "2017-01-19T22:21:02.959Z",
            "Progress": 0,
            "OriginalVolumeType": "gp2",
            "OriginalIops": 300,
            "OriginalSize": 100
        },
        {
            "TargetSize": 2000,
            "TargetVolumeType": "sc1",
            "ModificationState": "modifying",
            "VolumeId": "vol-22222222222222222",
            "StartTime": "2017-01-19T22:23:22.158Z",
            "Progress": 0,
            "OriginalVolumeType": "gp2",
            "OriginalIops": 300,
            "OriginalSize": 1000
        }
    ]
}
```

The next example describes all volumes with a modification state of either `optimizing` or `completed`, and then filters and formats the results to show only modifications that were initiated on or after February 1, 2017:

```
aws ec2 describe-volumes-modifications \
    --filters Name=modification-state,Values="optimizing","completed" \
    --query "VolumesModifications[?StartTime>='2017-02-01'].{ID:VolumeId,STATE:ModificationState}"
```

The following is example output with information about two volumes:

```
[
    {
        "STATE": "optimizing",
        "ID": "vol-06397e7a0eEXAMPLE"
    },
    {
        "STATE": "completed",
        "ID": "vol-ba74e18c2aEXAMPLE"
    }
]
```

------
#### [ PowerShell ]

**To monitor progress of a modification**  
Use the [Get-EC2VolumeModification](https://docs.aws.amazon.com/powershell/latest/reference/items/Get-EC2VolumeModification.html) cmdlet. The following example describes the volume modifications for two volumes.

```
Get-EC2VolumeModification `
    -VolumeId vol-11111111111111111 vol-22222222222222222
```

------

**Note**  
Rarely, a transient AWS fault can result in a `failed` state. This is not an indication of volume health; it merely indicates that the modification to the volume failed. If this occurs, retry the volume modification.