このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
the specified gateway is not connected
対処
関連リンク
API Reference for AWS Storage Gateway - AWS Documentation
https://docs.aws.amazon.com/storagegateway/latest/userguide/AWSStorageGatewayAPI.html
AWS: aws_storagegateway_gateway - Terraform by HashiCorp
https://www.terraform.io/docs/providers/aws/r/storagegateway_gateway.html
pulumi-aws/gateway.ts at master ・ pulumi/pulumi-aws ・ GitHub
https://github.com/pulumi/pulumi-aws/blob/master/sdk/nodejs/storagegateway/gateway.ts
storagegateway - Pulumi
https://pulumi.io/reference/pkg/python/pulumi_aws/storagegateway/
Module storagegateway - Pulumi
https://pulumi.io/reference/pkg/nodejs/@pulumi/aws/storagegateway
AWS Storage Gateway. User Guide API Version - PDF
https://technodocbox.com/Network_Security/75955743-Aws-storage-gateway-user-guide-api-version.html