Oracle Cloud Infrastructure Documentation

Resizing a Volume

The Oracle Cloud Infrastructure Block Volume service lets you expand the size of block volumes and boot volumes. You have three 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. You can attach a volume and start using it as soon as it's resized and becomes available.

This topic describes how to expand your volume in place with offline resizing.


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

Required IAM Policy

To use Oracle Cloud Infrastructure, you must be given the required type of access in a An IAM document that specifies who has what type of access to your resources. It is used in different ways: to mean an individual statement written in the policy language; to mean a collection of statements in a single, named "policy" document (which has an Oracle Cloud ID (OCID) assigned to it); and to mean the overall body of policies your organization uses to control access to resources. written by an administrator, whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you try to perform an action and get a message that you don’t have permission or are unauthorized, confirm with your administrator the type of access you've been granted and which A collection of related resources that can be accessed only by certain groups that have been given permission by an administrator in your organization. you should work in.

For administrators: The policy in Let users launch 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. If you want to dig deeper into writing policies for instances, cloud networks, or other Core Services API resources, see Details for the Core Services.

Considerations When Resizing a Volume

Whenever you detach and re-attach 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 re-attach 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 re-attach 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.

Resizing a Volume Using the Console

Resizing a Block Volume
Resizing a Boot Volume for a Windows Instance
Resizing a Boot Volume for a Linux Instance