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EBS volume stuck in CloudFormation

When running CloudFormation, all the resources are being created with no problem. However it seems to be getting stuck at creating or mounting a volume. The CloudFormation fails and initiates a rollback. This is the error I am getting. 

Volume attachment between volume-id vol-xxxxxxxx and instance-id i-xxxxxxx at device /dev/xvda is attaching

This turned out to be a conflict on HVM EC2 instances because /dev/sda1 is being remapped to /dev/xvda. My second drive is also mapped to /dev/xvda. The fix was to simply to map it slightly different to avoid mapping conflict.

Here’s the original mapping.

Boot:   /dev/xvda
Device: /dev/xvda
Device: /dev/xvdb

Here’s the fix.

Boot:   /dev/xvda
Device: /dev/xvdb
Device: /dev/xvdc

GCP Identify Your Disks

Here’s how to identify your disks on the system to cross check with GCP Dashboard.

ls -l /dev/disk/by-id

Result:

[root@servername ~]# ls -l /dev/disk/by-id
total 0
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 google-boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-persistent-disk-1 -> ../../sdb
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 scsi-0Google_PersistentDisk_boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_persistent-disk-1 -> ../../sdb

Encrypt Volume via Terraform

Here’s the Terraform script to encrypt an unencrypted volume. It creates a snapshot, encrypts a snapshot, and encrypts the volume.

#
# Set Variables
#
variable "volume" {
  description = "The Volume to encrypt: vol-12345678901234567"
}
variable "region" {
  description = "The Region: us-east-2"
}
variable "az" {
  description = "The AZ: us-east-2a"
}
 
#
# Set Credentials
#
provider "aws" {
	access_key = "put-your-access-key-here"
	secret_key = "put-your-secret-key-here"
	region = "${var.region}"
}
 
/*
#
# Create Unencrypted Volume
#
resource "aws_ebs_volume" "unencrypted_volume" {
  availability_zone = "${var.az}"
  size              = 10
  tags = {
    Name = "Unencrypted_Volume"
  }
}
*/
 
#
# Create Unencrypted Snapshot
#
resource "aws_ebs_snapshot" "unencrypted_snapshot" {
  #volume_id = "${aws_ebs_volume.unencrypted_volume.id}"
  volume_id = "${var.volume}"
  tags = {
    Name = "Unencrypted_Snapshot"
  }
}
 
#
# Create Encrypted Snapshot
#
resource "aws_ebs_snapshot_copy" "encrypted_snapshot" {
  source_snapshot_id = "${aws_ebs_snapshot.unencrypted_snapshot.id}"
  source_region      = "${var.region}"
  encrypted = true
  tags = {
    Name = "Encrypted_Snapshot"
  }
}
 
#
# Created Encrypted Volume
#
resource "aws_ebs_volume" "encrypted_volume" {
  availability_zone = "${var.az}"
  snapshot_id = "${aws_ebs_snapshot_copy.encrypted_snapshot.id}"
  tags = {
    Name = "Encrypted_Volume"
  }
}