Partial resources migration with `backend migrate`

Author: TenshoCreated Jun 15, 2026Updated Sep 14, 2026

Labelsenhancementpreserved

Describe the enhancement

Sometimes I want not barely rearrange units rather split them into multiple ones and comprise a stack. It would be handy if amazing time-saver terragrunt backend migrate command would accept the list of resource addresses to move across the state boundaries.

Terraform

BEFORE

mega
  abc.tf
  main.tf
  xyz.tf

# AFTER

abc
  main.tf

small
  main.tf

xyz
  main.tf

Terragrunt

BEFORE

mega-
  terragrunt.hcl <== split state into multiple ones during refactoring

AFTER

mega
  abc
    terragrunt.hcl
  small
    terragrunt.hcl
  xyz
    terragrunt.hcl

$ terragrunt backend migrate mega mega/abc --addresses module.abc.null_resource.a null_resource.default

Additional context

Terraform used to have similar functionality for local backend in the past:

bash

$ terraform state mv -state=mega.tfstate -state-out=abc.tfstate module.abc.null_resource.a module.abc.null_resource.b module.abc.null_resource.c

However:

bash

$ terraform state mv --help
...
  -state, state-out, and -backup are legacy options supported for the local
  backend only. For more information, see the local backend's documentation.

RFC Not Needed

I have evaluated the complexity of this enhancement, and I believe it does not require an RFC.

Source: gruntwork-io/terragrunt

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