Updated 2023-08-29

Attaching a Block Volume to an Instance

Attach a block volume to a compute instance to expand the available storage on the instance.

If you specify iSCSI as the volume attachment type, you must also connect and mount the volume from the instance for the volume to be usable. For more information, see Volume Attachment Types and Connecting to a Block Volume.

You can attach volumes to more than one instance at a time. For more information, see Attaching a Volume to Multiple Instances. To prevent data corruption from uncontrolled read/write operations with multiple instance volume attachments you must install and configure a clustered file system before you can use the volume. For more information, see Configuring Multiple Instance Volume Attachments with Read/Write Access.

Note

When you change the performance for a volume, the volume's lifecycle state changes to Provisioning while the settings are being updated. During this process, you can't attach the volume to an instance. You must wait until the volume's lifecycle state transitions back to Available before you attach the volume to an instance.

Attaching Ultra High Performance Volumes

When you attach a volume configured for the Ultra High Performance level, the volume attachment must be enabled for multipath to optimize the volume's performance.

The Block Volume service attempts to configure the attachment as multipath-enabled during the attachment process. After you attach a volume, you can confirm if the volume attachment was successfully enabled for multipath. See Checking if a Volume Attachment is Multipath-Enabled.

Whether an attachment is enabled for multipath is determined based the attached instance's shape, along with whether all the applicable prerequisites are met and configured correctly. For more information about prerequisites and requirements for multipath-enabled attachments, see Configuring Attachments to Ultra High Performance Volumes.

For more information about the Ultra High Performance level, see Block Volume Performance and Ultra High Performance.

Security Zones

Security Zones ensure that your cloud resources comply with Oracle security principles. If any operation on a resource in a security zone compartment violates a policy for that security zone, then the operation is denied.

The following security zone policies affect your ability to attach block volumes to compute instances.

  • All block volumes attached to a compute instance in a security zone must be in the same security zone.

  • Block volumes in a security zone can't be attached to a compute instance that is not in the same security zone.