Updated 2024-06-04

Resizing a Volume

The Oracle Cloud Infrastructure Block Volume service lets you expand the size of block volumes and boot volumes. You have several options to increase the size of your volumes:

For more information about the Block Volume service, see the Block Volume FAQ.

You can only increase the size of the volume, you cannot decrease the size.

Note

If cross-region replication is enabled for the volume you want to resize, before you resize the volume, you must disable cross-region replication. Once the volume is resized, you can renable cross-region replication for the volume. For more information about this feature, see Replicating a Volume.
Note

Resizing IDE type boot volumes is not supported. This applies to both offline and online resizing. To workaround this limitation, you can do one of the following:

  • Terminate the VM instance, ensuring that you keep the boot volume when you terminate the instance. Resize the boot volume that you have kept, and then launch a new VM instance, using the resized boot volume as the image source.

  • Create a clone of the boot volume, resize the boot volume clone, and then launch a new VM instance using the resized boot volume clone as the image source.

Caution

Before you resize a boot or block volume, you should create a backup of the volume.
Note

After a volume has been resized, the first backup on the resized volume will be a full backup. See Volume Backup Types for more information about full versus incremental volume backups.

Required IAM Policy

To use Oracle Cloud Infrastructure, you must be granted security access in a policy  by an administrator. This access is required whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you get a message that you don't have permission or are unauthorized, verify with your administrator what type of access you have and which compartment  to work in.

For administrators: The policy in Let users launch compute instances includes the ability to attach/detach existing block volumes. The policy in Let volume admins manage block volumes, backups, and volume groups lets the specified group do everything with block volumes and backups, but not launch instances.

If you're new to policies, see Getting Started with Policies and Common Policies. For reference material about writing policies for instances, cloud networks, or other Core Services API resources, see Details for the Core Services.

Online Resizing of Block Volumes Using the Console

With online resizing, you can expand the volume size without detaching the volume from an instance.

Offline Resizing of Block Volumes Using the Console

With offline resizing, you detach the volume from an instance before you expand the volume size. Once the volume is resized and reattached, you need to extend the partition, but you do not need to rescan the disk.

Considerations When Resizing an Offline Volume

Whenever you detach and reattach volumes, there are complexities and risks for both Linux-based and Windows-based instances. This applies to both paravirtualized and iSCSI attachment types. You should keep the following in mind when resizing volumes:

  • When you reattach a volume to an instance after resizing, if you are not using consistent device paths, or the instance does not support consistent device paths, device order and path may change. If you are using a tool such as Logical Volume Manager (LVM), you may need to fix the device mappings. For more information about consistent device paths, see Connecting to Volumes With Consistent Device Paths.

  • When you detach and then reattach an iSCSI-attached volume to an instance, the volume's IP address will increment.

  • Before you resize a volume, you should create a full backup of the volume.