Copy Snapshot to Azure Blob Storage with AzCopy

Question

A snapshot of size 8192 GiB exists in the EastUS region. The goal is to copy it to a Storage Blob account located in Central India. However, while using the AzCopy command, an error related to content-length occurs, indicating it only accepts Page Blobs up to 8TB. Despite the snapshot being 8TB, the following error message is received:

<Code>InvalidHeaderValue</Code><Message>The value for one of the HTTP headers is not in the correct format. </Message><HeaderName>x-ms-blob-content-length</HeaderName><HeaderValue>8796093022720</HeaderValue>

No content-length has been specified in the AzCopy command used, which is as follows:

azcopy copy "SAS URL of the Snapshot" "https://<Account-name>.blob.core.windows.net/<container-name>/<blob-name>.vhd" --recursive=true

What steps should be taken to successfully copy this snapshot to the Storage account?

Answer 1

Hi Ankit Godara,
Welcome to Microsoft Q&A Forum, thank you for posting your query here!
The error with AzCopy is due to the limitation on the size of Page Blobs, which can only be up to 8TB. The error message indicates that the x-ms-blob-content-length header value exceeds this limit.
Verify the Snapshot Size: Ensure that the snapshot size is indeed 8192 GiB (8 TiB). If it's slightly over, it might cause issues with the content-length header.

1. Use the Correct Blob Type: AzCopy supports copying Page Blobs up to 8 TiB. Ensure that the destination blob is a Page Blob and not a Block Blob, as Block Blobs have different size limitations.
2. Check AzCopy Version: Make sure you are using the latest version of AzCopy. You can download the latest version from https://learn.microsoft.com/en-us/azure/storage/common/storage-use-azcopy-v10?tabs=dnf
3. Specify the Blob Type: Explicitly specify the blob type in your AzCopy command.
   Use Azure CLI as an Alternative: If AzCopy continues to give issues, you can use the Azure CLI to copy the snapshot.
   Ensure there are no network issues that might be causing the header value to be incorrectly formatted. Check the AzCopy logs for more detailed error messages. This can provide additional insights into what might be going wrong.

If you have any other questions or are still running into more issues, let me know in the "comments" and I would be happy to help you