Blob mounting in Amazon ECR
Amazon ECR supports a capability called blob mounting to share common image layers across repositories within a registry. When enabled, repositories within a single registry can reference layers from other repositories within the same registry instead of storing duplicate copies.
When registry blob mounting is enabled, Amazon ECR checks for existing layers in your registry during push operations when mounting parameters are included. If a layer already exists in another repository within the same registry, Amazon ECR will mount the existing layer instead of uploading a duplicate.
Note
OCI clients automatically include mounting parameters if they detect a blob may already exist in a different repository. Amazon ECR attempts mounting only when these parameters are present in the client's POST request.
Blob mounting concepts
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Blob mounting only works within the same registry (same account and region).
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Repositories must use identical encryption type and keys.
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Blob mounting is not supported for images created via pull through cache.
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If you decide to disable blob mounting, existing images that were pushed with blob mounting configured will continue to work and layers will remain mounted.
Blob mounting configuration
You can use the Amazon Web Services Management Console or Amazon CLI to configure blob mounting for your registry.