Oracle Cloud Infrastructure Documentation

Boot Volumes

When you launch a virtual machine (VM) or bare metal instance based on an Oracle-provided image or custom image, a new boot volume for the instance is created in the same compartment. That boot volume is associated with that instance until you terminate the instance. When you terminate the instance, you can preserve the boot volume and its data. For more information, see Terminating an Instance. This feature gives you more control and management options for your compute instance boot volumes, and enables:

  • Instance scaling: When you terminate your instance, you can keep the associated boot volume and use it to launch a new instance using a different instance type or shape. See Creating an Instance for steps to launch an instance based on a boot volume. This allows you to switch easily from a bare metal instance to a VM instance and vice versa, or scale up or down the number of cores for an instance.

  • Troubleshooting and repair: If you think a boot volume issue is causing a compute instance problem, you can stop the instance and detach the boot volume. Then you can attach it to another instance as a data volume to troubleshoot it. After resolving the issue, you can then reattach it to the original instance or use it to launch a new instance.

Boot volumes are encrypted by default, the same as other block storage volumes. For more information, see Block Volume Encryption.


In-transit encryption for boot and block volumes is only available for virtual machine (VM) instances launched from Oracle-provided images, it is not supported on bare metal instances. It is also not supported in most cases for instances launched from custom images imported for "bring your own image" (BYOI) scenarios. To confirm support for certain Linux-based custom images and for more information contact Oracle support, see Getting Help and Contacting Support.

You can group boot volumes with block volumes into the same volume group, making it easy to create a group volume backup or a clone of your entire instance, including both the system disk and storage disks at the same time. See Volume Groups for more information.

You can move Block Volume resources such as boot volumes and boot volume backups between compartments. For more information, see Move Block Volume Resources Between Compartments.

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

Custom Boot Volume Sizes

When you launch an instance, you can specify whether to use the selected image's default boot volume size, or you can specify a custom size up to 32 TB. This capability is available for the following image source options:

  • Oracle-provided image

  • Custom image

  • Image OCID

See Creating an Instance for more information.

The specified size must be larger than the image's default boot volume size or 50 GB, whichever is higher. After you launch the instance, you can't change the boot volume size.


The minimum size for Windows-based image boot volumes is 256 GB.

If you specify a custom boot volume size, you need to extend the volume to take advantage of the larger size. For steps, see Extending the Partition for a Boot Volume.

Required IAM Service 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 Compute instances includes the ability to list boot volumes. The policy in Let volume admins manage block volumes, backups, and volume groups lets the specified group do everything with block volumes, boot 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.

Using the Console

To access the Console, you must use a supported browser.

See the following tasks for managing boot volumes:

Using the API

For information about using the API and signing requests, see REST APIs and Security Credentials. For information about SDKs, see Software Development Kits and Command Line Interface.

Use these API operations to manage boot volumes: