Connecting to Volumes With Consistent Device Paths

Oracle Cloud Infrastructure supports consistent device paths for block volumes that are attached to compatible Linux-based instances. When you attach a block volume to an instance, you must select a device path that remains consistent between instance reboots. This enables you to use a consistent device path when you refer to the volume to perform tasks such as:

When you use consistent device paths on compatible Linux-based instances, the boot volume's device path is:


Device paths are not available when you attach a boot volume as a data volume to a second instance.

Images that Support Consistent Device Paths

Consistent device paths are supported on instances when all of the following things are true:

For instances launched using the image OCID or an existing boot volume, if the source image supports consistent device paths, the instance supports device paths.

Consistent device paths are not supported on Linux-based partner images or custom images that are created from other sources. This feature does not apply to Windows-based images.


You must select a device path when you attach a volume using the Console, it is required. Specifying a device path is optional when you attach a volume using the CLI, REST APIs, or SDK.

Device Paths in the Console

You select a device path when you attach a block volume to an instance.

If you specify a device path, the path appears in the Attached Block Volumes list for an instance, in the Device Path field. An example is shown in the following screenshot.

The device path field for an attached block volume.

Device Paths on the Instance

Use the following sample commands to perform various configuration tasks on the attached volume. Commands are provided for volumes that use consistent device paths and for volumes that don't.

Creating a partition with fdisk
  • No device path specified:

    fdisk /dev/sdb
  • Device path specified:

    fdisk /dev/oracleoci/oraclevdb
Creating an ext3 file system
  • No device path specified:

    /sbin/mkfs.ext3 /dev/sdb1
  • Device path specified:

    /sbin/mkfs.ext3 /dev/oracleoci/oraclevdb1
Updating the /etc/fstab file
  • No device path specified:

    UUID=84dc162c-43dc-429c-9ac1-b511f3f0e23c /oradiskvdb1 xfs defaults,_netdev,noatime 0 2
  • Device path specified:

    /dev/oracleoci/oraclevdb1   /oradiskvdb1    ext3    defaults,_netdev,noatime  0  2
Mounting the file system
  • No device path specified:

    mount /dev/sdb1 /oradiskvdb1
  • Device path specified:

    mount /dev/oracleoci/oraclevdb1 /oradiskvdb1