attach vol is lost after resize

main.tf

variable "flavor_name" {
  default = "c2-7"
}

provider "openstack" {
  region = "GRA3"
}

# Import Keypair
resource "openstack_compute_keypair_v2" "keypair" {
  name       = "trash-keypair"
  public_key = "${file("~/.ssh/id_rsa.pub")}"
}

resource "openstack_networking_secgroup_v2" "sg" {
  name = "trash_sg"
}

resource "openstack_networking_secgroup_rule_v2" "in_22_traffic" {
  direction         = "ingress"
  ethertype         = "IPv4"
  protocol          = "tcp"
  remote_ip_prefix  = "0.0.0.0/0"
  port_range_min    = 22
  port_range_max    = 22
  security_group_id = "${openstack_networking_secgroup_v2.sg.id}"
}

resource "openstack_blockstorage_volume_v2" "myvol" {
  name = "myvol"
  size = 5
}

data "openstack_images_image_v2" "debian7" {
  name        = "Debian 7"
  most_recent = true
}

resource "openstack_compute_instance_v2" "test" {
  name            = "pci-1342"
  flavor_name     = "${var.flavor_name}"
  image_id        = "${data.openstack_images_image_v2.debian7.id}"
  key_pair        = "${openstack_compute_keypair_v2.keypair.name}"
  security_groups = ["${openstack_networking_secgroup_v2.sg.name}"]

  network {
    name = "Ext-Net"
  }

  block_device {
    uuid                  = "${data.openstack_images_image_v2.debian7.id}"
    source_type           = "image"
    destination_type      = "local"
    boot_index            = 0
    delete_on_termination = true
  }

  block_device {
    uuid                  = "${openstack_blockstorage_volume_v2.myvol.id}"
    source_type           = "volume"
    destination_type      = "volume"
    boot_index            = 1
    delete_on_termination = true
  }
}

output "public_ipv4" {
  value = "ssh debian@${openstack_compute_instance_v2.test.access_ip_v4}"
}

script.sh

source [openrc.sh]
terraform init
terraform apply -auto-approve
... ssh debian@...
... $ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT                                                                                                                                                        [245/884]
vda    254:0    0     5G  0 disk
sda      8:0    0   100G  0 disk
└─sda1   8:1    0   100G  0 part /
terraform apply -auto-approve -var flavor_name=c2-15
... ssh debian@...
... $ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT                                                                                                                                                        [245/884]
vda    254:0    0     5G  0 disk
sda      8:0    0   100G  0 disk
└─sda1   8:1    0   100G  0 part /
terraform destroy -auto-approve

block_device {
boot_index = 1
delete_on_termination = true
destination_type = "volume"
source_type = "blank"
volume_size = "${var.volume_size_orchestrator}"
}

j'ai mis plein de données dans le vg02