4.4. Managing volumes¶

4.4.1. Creating, editing, and removing volumes¶

To create a volume, do the following:

1. On the Volumes screen, click Create volume.

   

2. In the Create volume window, specify a volume name and size in gigabytes, select a storage policy, and then click Create.

To edit a volume, select it, and then click the pencil icon next to a parameter you need to change. Note the following restrictions:

• You cannot shrink volumes.
• To extend volumes that are in use, stop the VM first.
• You cannot change the volume redundancy type.

To remove a volume, click its ellipsis button, and then click Delete. To remove multiple volumes at once, select them, and then click Delete. To remove a volume that is in use, detach it first.

4.4.2. Cloning volumes¶

You can clone volumes that are not attached to VMs or attached to stopped VMs. To clone a volume, do the following:

1. On the Volumes screen, click a volume.

2. In the volume panel that opens, click Clone.

   

3. In the Clone volume window that opens, specify a volume name, size, and storage policy. Click Clone.

   

4.4.3. Attaching and detaching volumes¶

To add a writable virtual disk drive to a VM, attach a volume to it. To do this:

1. On the Volumes screen, click the ellipsis button next to an unused volume, and then click Attach.

2. In the Attach volume window, select the VM from the drop-down list, and then click Done.

   

To detach a volume, do the following:

1. Click the ellipsis button next to the volume that is in use.

2. If the VM is not running, click Detach.

3. If the VM is running, you can only click Force detach to immediately detach the volume.

   Warning

   There is a risk of data loss.

4.4.4. Creating images from volumes¶

To create multiple VMs with the same boot volume, you can create an image from an existing boot volume and deploy VMs from it. Make sure to install cloud-init in the volume before creating the image.

Do the following:

1. Power off the VM that the original volume is attached to.

2. Switch to the Volumes screen, click volume’s ellipsis button, and then click Create image.

   

3. In the Create image window, enter an image name, and then click Create.

   

The new image will appear on the Images tab.

4.4.5. Managing volume snapshots¶

You can save the current state of a VM file system or user data by creating a snapshot of a volume. A snapshot of a boot volume may be useful, for example, before updating VM software. If anything goes wrong, you will be able to revert the VM to a working state at any time. A snapshot of a data volume can be used for backing up user data and testing purposes.

To create a snapshot of a volume, do the following:

1. On the Volumes screen, click a volume.

2. In the volume panel that opens, switch to Snapshots, and then click Create snapshot.

   

   Note

   To create a consistent snapshot of a running VM’s volume, make sure the guest tools are installed in the VM. The QEMU guest agent included in the guest tools image automatically quiesces the filesystem during snapshotting. For instructions on installing the guest tools, refer to Installing guest tools.

Once the snapshot is created, you can see and manage it on the Snapshots tab on the volume right pane.

You can do the following:

• Create a new volume from the snapshot.

• Create a template from the snapshot.

• Discard all changes that have been made to the volume since the snapshot was taken. This action is available only for VMs with the “Shut down” and “Shelved offloaded” statuses.

  Warning

  As each volume has only one snapshot branch, all snapshots created after the snapshot you are reverting to will be deleted. If you want to save a subsequent snapshot before reverting, create a volume or an image from it first.

• Change the snapshot name and description.

• Reset the snapshot stuck in an “Error” state or transitional state to the “Available” state.

• Remove the snapshot.

To perform these actions, click the ellipsis button next to a snapshot, and then click the corresponding action.