Use this operation to set the account preference in the current Amazon Web Services Region to use long 17 character (63 bit) or short 8 character (32 bit) resource IDs for new EFS file system and mount target resources. All existing resource IDs are not affected by any changes you make. You can set the ID preference during the opt-in period as EFS transitions to long resource IDs. For more information, see Managing Amazon EFS resource IDs.
Starting in October, 2021, you will receive an error if you try to set the account preference to use the short 8 character format resource ID. Contact Amazon Web Services support if you receive an error and must use short IDs for file system and mount target resources.