> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blinkops.com/llms.txt
> Use this file to discover all available pages before exploring further.
# EBS Put Snapshot Block
Writes a block of data to a snapshot. If the specified block contains data, the existing data is overwritten. The target snapshot must be in the `pending` state.
Data written to a snapshot must be aligned with 512-KiB sectors.
External Documentation
To learn more, visit the [AWS documentation](https://docs.aws.amazon.com/ebs/latest/APIReference/API_PutSnapshotBlock.html).
## Basic Parameters
| Parameter | Description |
| ------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| AWS Region(s) | Enter the desired AWS Region(s).
To execute the action in multiple regions, provide a comma-separated list.
For example: `us-east-1,eu-west-2`.
If you wish to run the action in all available regions, use the asterisk symbol (`*`) instead. |
| Block Data | The data to write to the block.
The block data is not signed as part of the Signature Version 4 signing process. As a result, you must generate and provide a Base64-encoded SHA256 checksum for the block data using the **x-amz-Checksum** header. Also, you must specify the checksum algorithm using the **x-amz-Checksum-Algorithm** header. The checksum that you provide is part of the Signature Version 4 signing process. It is validated against a checksum generated by Amazon EBS to ensure the validity and authenticity of the data. If the checksums do not correspond, the request fails. For more information, see [Using checksums with the EBS direct APIs](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-accessing-snapshot.html#ebsapis-using-checksums) in the *Amazon Elastic Compute Cloud User Guide*. |
| Block Index | The block index of the block in which to write the data. A block index is a logical index in units of `512` KiB blocks. To identify the block index, divide the logical offset of the data in the logical volume by the block size (logical offset of data/ `524288`). The logical offset of the data must be `512` KiB aligned. |
| Checksum | A Base64-encoded SHA256 checksum of the data. Only SHA256 checksums are supported. |
| Checksum Algorithm | The algorithm used to generate the checksum. Currently, the only supported algorithm is `SHA256`. |
| Data Length | The size of the data to write to the block, in bytes. Currently, the only supported size is `524288` bytes.
Valid values: `524288`. |
| Snapshot ID | The ID of the snapshot. |
## Advanced Parameters
| Parameter | Description |
| -------------------------------- | ----------------------------------------------------------------------------- |
| Disable XML To JSON Auto Convert | When checked, XML responses are not automatically converted into JSON format. |
| Progress | The progress of the write process, as a percentage. |
## Example Output
```json theme={"dark"}
{}
```
## Workflow Library Example
[Ebs Put Snapshot Block with Aws and Send Results Via Email](https://library.blinkops.com/workflows/ebs-put-snapshot-block-with-aws-and-send-results-via-email)
Preview this Workflow on desktop