Create a volume

Volumes are an essential part of OpenStack to store your data. Volumes are block storage devices that are attached to instances. They are independent from the life cycle of the instance, and can be attached and detached to instances as needed.

This articles will guide you through the process of creating a volume.

Using the OpenStack Dashboard

Creating a volume through the OpenStack Dashboard is a simple process.

Step 1
Log in to the OpenStack Dashboard

Step 2
Navigate to the VOLUMES section and click on Volumes

Step 3
Click on Create Volume button right above the volume list.

Step 4
Fill in the details of the volume you want to create. You can specify the size of the volume, the availability zone, and the volume type. Please feel free to change any of the example settings to your needs.

  • Volume Name: data-volume
  • Description: This is a volume for storing data
  • Volume Source: NO SOURCE, EMPTY VOLUME (please see the note below)
  • Type: SSD (please see the note below)
  • Size (GiB): 10
  • Availability Zone: ANY AVAILABILITY ZONE (please see the note below)
  • Group: NO GROUP (please see the note below)

Note: The Volume Source field is used to create a volume from an existing volume, snapshot, or image. If you want to create an empty volume, select NO SOURCE, EMPTY VOLUME.

Note: The Type field is often used to provide different specifications or storage tiers. Some volume types might support volume encryption as well. Most OpenStack providers provide distinct naming for encrypted volume types.

Note: The Availability Zone field is used to specify the availability zone where the volume will be created. This is important since volumes cannot be attached to instances in different availability zones.

Note: The Group field is used to specify the volume group where the volume will be created. This is can be a handy tool if you have multiple volume in your OpenStack environment and want to group them together.

Step 5
Click on the small arrow button behind the newly created volume to see actions menu and click on Manage Attachments

Step 6
Select the instance you want to attach the volume to and click on Attach Volume to attach the volume to the instance.

Using the OpenStack CLI

Creating a volume through the OpenStack CLI can be a bit more complicated than using the OpenStack Dashboard, but when you get the hang of it, it can be a powerful tool.

Step 1
First make sure you have setup the OpenStack CLI and that you are able to execute commands using the openstack command. For more information please refer to the Using the OpenStack CLI article.

Step 2
Run the following command to create a volume:

openstack volume create --size <volume_size --type <volume_type> --availability-zone <availability_zone> <volume_name>

Note: The volume_type is often used to provide different specifications or storage tiers. Some volume types might support volume encryption as well. Consult the documentation of your OpenStack providers to select the proper volume type.

Step 3
Check the status of the volume by running the following command:

openstack volume show <volume_name>

Step 4
Attach the volume to an instance by running the following command:

openstack server add volume <instance_name/instance_id> <volume_name/volume_id>

Mounting the volume within the instance

After you have created and attached the volume to an instance, you can mount the volume within the instance. The process of mounting a volume is different for each operating system.

Be default the volume is just empty diskspace which you can use as you like. The following steps will guide you through the process of mounting the volume an adding an filesystem to it so you can use it to store your data.

Instruction for Linux

Instruction for Windows

Linux

Step 1
You can identify the volume by its size and mountpoint. For example, if the volume is 10GB and has no mountpoint, it is likely the volume you just created. it will probably look simular to /dev/sdb but it may be different.

List the available disks on the instance by running the following command:

lsblk

Note: The mountpoint displayed in OpenStack might not be the same as the mountpoint in the instance.

Step 2
Create a new partition on the volume by running the following command:

sudo fdisk <volume>

Step 3
Format the partition by running the following command:

sudo mkfs.ext4 <volume>

Note: You can choose any filesystem to format the partition. In this example, we are using ext4.

Step 4
Create a new directory to mount the volume by running the following command:

sudo mkdir /mnt/data-volume

Note: You can choose any directory to mount the volume. In this example, we are using /mnt/data-volume.

Step 5
Mount the volume by running the following command:

sudo mount <volume> /mnt/data-volume

You can now use the volume to store your data.

Mounting the volume automatically

If you want to mount the volume automatically after a reboot, we need to add an entry to the /etc/fstab file.

When managing multiple volumes on a single instance, it might be more feasible to use the procedure on Identify cinder volumes from within the instance. Or use the steps below. Both procedures result in an automatically mounted volume

Step 1
First we need to identify the volume by its UUID. You can do this by running the following command:

You are looking for the UUID of the volume you just created. It will probably look something like 85ca773c-a78b-415e-b1cd-2c4f1a1d267f. Make sure you copy the UUID of the correct volume. it should be the same path as in the steps above (for example: /dev/sdb).

sudo blkid

Step 2
Now we need to add an entry to the /etc/fstab file. We will use the UUID we found in the previous step to identify the volume.

sudo nano /etc/fstab

Now add the following line to the bottom of the file:

UUID=<linux_volume_id> /mnt/data-volume ext4 defaults 0 0

To save the file press CTRL + X, then Y, and then ENTER.

Step 3
Test the /etc/fstab file by running the following command:

sudo mount -a

The volume should now be mounted automatically after a reboot. If you received an error, please check the /etc/fstab file for any errors.

Windows

Step 1
Right-click the windows logo in the left bottom corner and click on Disk Management.

Step 2
Right click on the Disk you want to prepare and online the disk to be able to use the disk.

Step 3
Right click on the Disk you want to prepare and click on Initialize Disk.

Step 4
In the Initialize Disk window, select the disk you want to initialize, select the GPT (GUID Partition Table) and click on OK.

Step 5
Right click on the unallocated space and click on New Simple Volume. You can just click on Next in the New Simple Volume Wizard to use the default settings. You can change the drive letter and the volume label if you want.

Your disk is now ready to use, you can access it through Window Explorer and use the disk to store you data.