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Creating and configuring an Additional Disk on an instance

Stephanie R.
Updated

Learn how to add a block storage volume to your public cloud project and configure it on your instance.

It is possible to create additional disks for your Public Cloud instances. This can be useful in cases where:

  • You want to increase your storage capacity without changing the instance model.
  • You want to have highly available, high-performance storage.
  • You want to move your storage and data to another instance.
  • You want to prepare the environment if you want to use Terraform.

 

Requirements

 

Instructions

The different types of volumes

OVHcloud offers three types of Block Storage volumes, each tailored to specific needs in terms of performance, capacity, and cost. These solutions enable you to attach persistent storage volumes to your instances, guaranteeing a high-level of reliability and availability.

More information about the types of volumes is available on our website.

 

Adding a new volume

Via the OVHcloud Control Panel

From the OVHcloud Control Panel:, navigate to the Block Storage section via the Public Cloud menu.

Click Create a volume.

manager_blockStorage_onboarding.png

Select the location for your block storage volume and click Next. For more information about Local Zones, see this guide.

NOTE: Your volume must be created in the same region as the instance to which you wish to attach it. If you create it in another region, you can delete it and recreate it in the correct region, or you can migrate the region by following this guide.

manager_blockStorage_order_region.png

Choose your volume type and click Next. More information about the types of volumes is available on our website.

manager_blockStorage_order_volumeType.png

From here, complete your volume's configuration by selecting the Volume capacity and Volume name, and then clicking Create the volume.

Once your new disk is available, click the more options ... button to the right of the disk and select Attach to instance.

In the pop-up window, choose an available instance and click Confirm. If no instances are available it is because you do now have an instance in a region matching that of the additional disk.

PCI_blockstorage_gettingstarted04.png

The process may take a few minutes to complete.

NOTE: Navigating away from the page during creation may interrupt the process.

Via Terraform

To create a simple block storage volume, you need three elements:

  • The name of the volume
  • The region
  • The size of the volume in GB

In our example, we will create a block storage in the US-EAST-VA region with a size of 10 GB. Add the following lines to a file named simple_blockstorage.tf:

# Creation of a block storage volume
resource "openstack_blockstorage_volume_v3" "terraform_blockstorage" {
name   = "terraform_blockstorage" # Name of the block storage volume
size   = 10                       # Volume size
region = "US-EAST-VA"                  # Region where the volume must be created
}

Then we will attach it to the target instance.

The instance and the volume must be in the same region.

Add the following lines below the previous ones:

# Attach the volume to the instance
resource "openstack_compute_volume_attach_v2" "volume_attach" {
  instance_id = "<your_instance_id>"
  volume_id   = openstack_blockstorage_volume_v3.terraform_volume.id
}

You can create your block storage volume and attach it to the desired instance by entering the following command:

terraform apply

The output should look like this:

$ terraform apply
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # openstack_blockstorage_volume_v3.terraform_blockstorage will be created
  + resource "openstack_blockstorage_volume_v3" "terraform_blockstorage" {
      + attachment        = (known after apply)
      + availability_zone = (known after apply)
      + id                = (known after apply)
      + metadata          = (known after apply)
      + name              = "terraform_blockstorage"
      + region            = "US-EAST-VA"
      + size              = 10
      + volume_type       = (known after apply)
    }

  # openstack_compute_volume_attach_v2.volume_attach will be created
  + resource "openstack_compute_volume_attach_v2" "volume_attach" {
      + device      = (known after apply)
      + id          = (known after apply)
      + instance_id = "11cc1279-xxxx-xxxx-xxxx-3ace4c954780"
      + region      = (known after apply)
      + volume_id   = (known after apply)
    }

Plan: 2 to add, 0 to change, 0 to destroy.

Do you want to perform these actions in workspace "test_terraform"?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

openstack_blockstorage_volume_v3.terraform_blockstorage: Creating...
openstack_blockstorage_volume_v3.terraform_blockstorage: Still creating... [10s elapsed]
openstack_blockstorage_volume_v3.terraform_blockstorage: Creation complete after 12s [id=daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]
openstack_compute_volume_attach_v2.volume_attach: Creating...
openstack_compute_volume_attach_v2.volume_attach: Still creating... [10s elapsed]
openstack_compute_volume_attach_v2.volume_attach: Creation complete after 14s [id=11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]

Apply complete! Resources: 2 added, 0 changed, 0 destroyed.

 

Configuring the new disk

The examples below presume you are logged in as a user with elevated permissions.

Using Linux

Establish an SSH connection to your instance, then use the command below to list the attached disks.

sda in this example refers to the default disk of the instance. The additional disk will then be labeled sdb.

lsblk
NAME    MAJ:MIN  RM    SIZE  RO  TYPE  MOUNTPOINTS
sda       8:0     0     50G   0  disk 
└─sda1    8:1     0   49.9G   0  part  /
sdb       8:16    0     10G   0  disk

Create a partition on the additional disk using the commands below.

If your additional disk is less than 2TB:

sudo fdisk /dev/sdb
Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x95c4adcc.

Command (m for help): n

Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-20971519, default 20971519):

Created a new partition 1 of type 'Linux' and of size 10 GiB.

Command (m for help): w

The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

If your additional disk is larger than 2TB:

sudo parted /dev/sdb
GNU Parted 3.5
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) help                                                             
  align-check TYPE N                       check partition N for TYPE(min|opt) alignment
  help [COMMAND]                           print general help, or help on COMMAND
  mklabel,mktable LABEL-TYPE               create a new disklabel (partition table)
  mkpart PART-TYPE [FS-TYPE] START END     make a partition
  name NUMBER NAME                         name partition NUMBER as NAME
  print [devices|free|list,all]            display the partition table, or available devices, or free space, or all found partitions
  quit                                     exit program
  rescue START END                         rescue a lost partition near START and END
  resizepart NUMBER END                    resize partition NUMBER
  rm NUMBER                                delete partition NUMBER
  select DEVICE                            choose the device to edit
  disk_set FLAG STATE                      change the FLAG on selected device
  disk_toggle [FLAG]                       toggle the state of FLAG on selected device
  set NUMBER FLAG STATE                    change the FLAG on partition NUMBER
  toggle [NUMBER [FLAG]]                   toggle the state of FLAG on partition NUMBER
  unit UNIT                                set the default unit to UNIT
  version                                  display the version number and copyright information of GNU Parted
(parted) mklabel gpt                                                      
(parted) mkpart primary 0 3750G                                           
Warning: The resulting partition is not properly aligned for best performance: 34s % 2048s != 0s
Ignore/Cancel? I                                                          
(parted) quit

Next, format the new partition sdb1 using the command below.

sudo mkfs.ext4 /dev/sdb1
mke2fs 1.42.12 (29-Aug-2014)
Creating filesystem with 2621184 4k blocks and 655360 inodes
Filesystem UUID: 781be788-c4be-462b-b946-88429a43c0cf
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Mount the partition with the following commands:

sudo mkdir /mnt/disk
sudo mount /dev/sdb1 /mnt/disk/

Finally, check the mount point using this command:

df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 9.8G 840M 8.6G 9% /
udev 10M 0 10M 0% /dev
tmpfs 393M 5.2M 388M 2% /run
tmpfs 982M 0 982M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 982M 0 982M 0% /sys/fs/cgroup
/dev/sdb1 9.8G 23M 9.2G 1% /mnt/disk

The mounting is not persistent because the disk will be detached when the instance reboots. To automate the mounting process, the fstab file needs to be edited.

First, retrieve the UUID (block ID) of the new volume:

sudo blkid
/dev/sda1: UUID="51ba13e7-398b-45f3-b5f3-fdfbe556f62c" TYPE="ext4" PARTUUID="000132ff-01"
/dev/sdb1: UUID="2e4a9012-bf0e-41ef-bf9a-fbf350803ac5" TYPE="ext4" PARTUUID="95c4adcc-01"

Open /etc/fstab with a text editor:

sudo nano /etc/fstab

Add the line below to the file and replace the UUID with your own:

UUID=2e4a9012-bf0e-41ef-bf9a-fbf350803ac5 /mnt/disk ext4 nofail 0 0

Save and exit the editor. The disk should be automatically mounted after every reboot from now on.

Using Windows

Establish a remote desktop (RDP) connection to your Windows instance.

Once logged in, right-click on the Start Menu button and open Disk Management.

PCI_blockstorage_gettingstarted05.png

The new disk will be displayed as an unknown volume with unallocated space.

PCI_blockstorage_gettingstarted06.png

If the disk is marked as offline here, it needs to be initialized first. You can use the Windows GUI or the DISKPART utility to achieve this. Otherwise, proceed with formatting the disk in Disk Management.

 

Initializing the disk in Disk Management

Right-click on the disk and select Online.

If the disk is marked as offline here, this is likely due to a policy in place on the instance. To fix this, right-click on the disk and select Online.

PCI_blockstorage_gettingstarted07.png

Then right-click it again and this time select Initialize Disk.

PCI_blockstorage_gettingstarted08.png

Next, select MBR (Master Boot Record) and click OK.

[primary]If your disk is more than 2TB, select GPT (GUID Partition Table).

PCI_blockstorage_gettingstarted09.png

 

Initializing the disk with DISKPART

Right-click on the Start Menu button and open Run.

PCI_blockstorage_gettingstarted10.png

Type cmd and click OK to open the command line application.

PCI_blockstorage_gettingstarted11.png

At the command prompt, open DISKPART:

C:\> diskpart

Use the following series of DISKPART commands to set the disk to online:

DISKPART> san

SAN Policy : Offline Shared

DISKPART> san policy = OnlineAll

DiskPart successfully changed the SAN policy for the current operating system .

- Implementation of the strategy on the extra disk:
[Code] DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 200 GB 0 B
* Disk 1 Offline 10 GB 1024 KB

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> attributes disk clear readonly

Disk attributes cleared successfully.

DISKPART> attributes disk

Current Read-only State : No
Read-only : No
Boot Disk : No
Pagefile Disk : No
Hibernation File Disk : No
Crashdump Disk : No
Clustered Disk : No

DISKPART> online disk

DiskPart successfully onlined the selected disk.

 

Formatting the disk

In Disk Management, right-click on the new disk and select New Simple Volume....

PCI_blockstorage_gettingstarted12.png

In the wizard, click Next to specify the volume size. It should be set to maximum by default. Click Next to continue.

PCI_blockstorage_gettingstarted13.png

Leave the new drive letter at default or select a different one, then click Next.

PCI_blockstorage_gettingstarted14.png

Label the volume (optional) and confirm the formatting options by clicking Next.

PCI_blockstorage_gettingstarted15.png

In the last window, click Finish to format the disk.

PCI_blockstorage_gettingstarted16.png

The disk will be available as a drive in File Explorer after the operation.

 

Detach a volume

If you wish to detach a volume from your instance, the best practice is to unmount the volume in the operating system before detaching it from the instance.

NOTE: An error message may appear if you have software or processes running on the additional disk. In this case, it is recommended to stop all processes before continuing.

Here is how to unmount the volume from the operating system before detaching it from the instance:

On Linux

Establish an SSH connection to your instance, then use the command below to list the attached disks.

lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 254:0 0 10G 0 disk
└─sda1 254:1 0 10G 0 part /
sdb       8:0    0   10G  0 disk
└─sdb1    8:1    0   10G  0 part /mnt/disk

Unmount the partition using the command below:

sudo umount /dev/sdb1

Remove the device ID from the fstab to complete the unmount process, if this is not done, the partition will be mounted right back after a reboot.

sudo nano /etc/fstab

Save and exit the editor.

On Windows

Establish a remote desktop (RDP) connection to your Windows instance.

Once logged in, right-click on the Start Menu button and open Disk Management.

PCI_blockstorage_gettingstarted17.png

Right-click on the volume you wish to unmount and select Change Drive Letter and Paths....

PCI_blockstorage_gettingstarted18.png

Click on Remove to remove the drive.

PCI_blockstorage_gettingstarted19.png

Next, click on Yes to confirm the disk removal.

PCI_blockstorage_gettingstarted20.png

When finished, you can close the Disk Management window.

 

Finally, we will detach the volume from the instance:

Via OVHcloud Control Panel

Go to the Public Cloud section of your OVHcloud Control Panel and click on Block Storage in the left-hand menu under Storage.

Click the ... button next to the corresponding volume and select Detach from instance.

NOTE: You can also cancel your Block Storage volume using this menu.

Click Confirm in the pop-up window to start the process.

PCI_blockstorage_gettingstarted21.png

Via Terraform

Start by deleting the lines previously created in your Terraform file:

# Attach the volume to the instance
resource "openstack_compute_volume_attach_v2" "volume_attach" {
  instance_id = "<your_instance_id>"
  volume_id   = openstack_blockstorage_volume_v3.terraform_volume.id
}

Enter the following command to check whether the correct resource will be deleted:

terraform plan

The output should look like this:

$ terraform plan
openstack_compute_volume_attach_v2.va_1: Refreshing state... [id=11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]
openstack_blockstorage_volume_v3.terraform_volume: Refreshing state... [id=daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  - destroy

Terraform will perform the following actions:

  # openstack_compute_volume_attach_v2.va_1 will be destroyed
  # (because openstack_compute_volume_attach_v2.va_1 is not in configuration)
  - resource "openstack_compute_volume_attach_v2" "va_1" {
      - device      = "/dev/sdb" -> null
      - id          = "11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806" -> null
      - instance_id = "11cc1279-xxxx-xxxx-xxxx-3ace4c954780" -> null
      - region      = "US-EAST-VA" -> null
      - volume_id   = "daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806" -> null
    }

Plan: 0 to add, 0 to change, 1 to destroy.

Then apply the changes by entering this command:

terraform apply

The output should look like this:

$ terraform apply
openstack_compute_volume_attach_v2.va_1: Refreshing state... [id=11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]
openstack_blockstorage_volume_v3.terraform_volume: Refreshing state... [id=daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  - destroy

Terraform will perform the following actions:

  # openstack_compute_volume_attach_v2.va_1 will be destroyed
  # (because openstack_compute_volume_attach_v2.va_1 is not in configuration)
  - resource "openstack_compute_volume_attach_v2" "va_1" {
      - device      = "/dev/sdb" -> null
      - id          = "11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806" -> null
      - instance_id = "11cc1279-xxxx-xxxx-xxxx-3ace4c954780" -> null
      - region      = "US-EAST-VA" -> null
      - volume_id   = "daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806" -> null
    }

Plan: 0 to add, 0 to change, 1 to destroy.

Do you want to perform these actions in workspace "test_terraform"?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

openstack_compute_volume_attach_v2.va_1: Destroying... [id=11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806]
openstack_compute_volume_attach_v2.va_1: Still destroying... [id=11cc1279-xxxx-xxxx-xxxx-3ace4c954780/daf3a86e-xxxx-xxxx-xxxx-ac7b6ffbb806, 10s elapsed]
openstack_compute_volume_attach_v2.va_1: Destruction complete after 17s

Apply complete! Resources: 0 added, 0 changed, 1 destroyed.

 

Go further

For more information and tutorials, please see our other Public Cloud support guides or explore the guides for other OVHcloud products and services.

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