Updated on 2024-03-18 GMT+08:00

Attaching an Existing System Disk

Scenarios

This section describes how to attach an existing system disk.

System disks can only be attached offline, which means that the server must be in the Stopped state.

You can view the disk function in the disk list. A disk can be attached to a server and used as the system disk only when its function is Bootable disk and its status is Available.

  • Bootable disks are the system disks detached from servers. A bootable disk can be re-attached to a server and be used as a system disk or data disk depending on the disk function selected.
  • Non-shared, yearly/monthly disks purchased together with or later added to a yearly/monthly ECS cannot be attached to other ECSs.

Constraints

  • Cloud servers created from ISO images are only used for OS installation. They have limited functions and cannot have EVS disks attached.
  • A non-shared disk can be attached to one server only.
  • The disk and the server must be in the same region and AZ.
  • A detached, non-shared yearly/monthly data disk purchased together with a server can only be re-attached to the original server and be used as a data disk.
  • A shared disk can be attached only when the servers' statuses are Running or Stopped.
  • A frozen disk cannot be attached.
  • A detached, yearly/monthly system disk purchased together with a server can be re-attached and used as a data disk for any server. If you want to use it again as a system disk, you must attach it to the original server.
  • A detached, pay-per-use system disk purchased together with a server can be re-attached and used as a data disk for any server. If you want to use it again as a system disk, you must attach it to a server that uses the same image as the original server.

Procedure

  1. Log in to the management console.
  2. Under Storage, click Elastic Volume Service.

    The disk list page is displayed.

  3. Locate the target disk in the list and click Attach.
  4. Select a server to attach the disk. Ensure that the disk and server are in the same AZ and that the server is in the Stopped state. After you select a server, System disk is automatically entered as the disk function for the server.

    One device name can be used for one disk only. For how to obtain the disk name in the OS, see section "How Do I Obtain My Disk Name in the ECS OS Using the Device Identifier Provided on the Console?" in the Elastic Cloud Server User Guide.

    Figure 1 Attach Disk

  5. Click OK to return to the disk list page.

    The status of the disk is Attaching, indicating that the disk is being attached to the server. When the function of the disk changes from Bootable disk to System disk and the disk status changes to In-use, the disk is successfully attached.

Related Operations

If your disk cannot be attached to a server, see Why Can't My Disk Be Attached?

For more attachment FAQs, see Attachment.