Detaching a Data Disk

Scenarios

If you want to use a data disk on another server in the same region and AZ, you can detach the data disk and then attach it to that server.

If a data disk is no longer required, you can detach it and then delete it.

Data disks can be detached online or offline, meaning that the server using the to-be-detached data disk can either be in the Running or Stopped state.

ECS
Detach an EVS disk from a running server. For details, see Detaching an EVS Disk from a Running ECS.
BMS
SCSI disks can be attached to BMSs and used as data disks. You can detach a data disk either from a running or stopped BMS.

For an attached data disk, the disk function is displayed as Data disk, and the disk status is displayed as In-use in the disk list. After the data disk has been detached from the server, the disk function remains unchanged, the disk status changes to Available for a non-shared data disk, and the disk status changes to Available for a shared data disk after it is detached from all its servers.

Precautions

Data may be lost after you detach an encrypted disk. For more information, see If I Detach a Disk, Will I Lose the Data on My Disk?

Prerequisites

Before detaching an EVS disk from a running Windows ECS, ensure that no programs are reading data from or writing data to the disk. Otherwise, data will be lost.

Before detaching an EVS disk from a running Linux ECS, you must log in to the ECS and run the umount command to cancel the association between the disk and the file system. In addition, ensure that no programs are reading data from or writing data to the disk. Otherwise, detaching the disk will fail.

Detaching a Non-shared Disk

Log in to the management console.
Under Storage, click Elastic Volume Service.
The disk list page is displayed.
Choose a way to detach the disk by determining whether you want to check server information first.
- If yes, perform the following procedure:
  1. In the disk list, click the name of the to-be-detached disk.
    The disk details page is displayed.
  2. Click the Servers tab to view the server where the target disk has been attached.
  3. Click to select the server and click Detach Disk.
    The Detach Disk dialog box is displayed.
  4. Click Yes to detach the disk.
- If no, perform the following procedure:
  1. In the disk list, locate the row that contains the target disk and choose More > Detach in the Operation column.
    The Detach Disk dialog box is displayed.
  2. Click Yes to detach the disk.
The disk list is displayed. The disk status is Detaching, indicating that the disk is being detached from the server.

When the status changes to Available, the disk is successfully detached.