Help Center/ Elastic Volume Service/ FAQs/ Attachment/ Can I Switch Between System Disks and Data Disks?
Updated on 2025-08-04 GMT+08:00

Can I Switch Between System Disks and Data Disks?

Whether you can switch between system and data disks depends on the disk billing mode.

  • If you detach a system disk and then attach it to another server as a data disk, the maximum capacity of this disk is still 1 TiB.
  • If you detach a system disk and then attach it to another server as a system disk, ensure that this server uses the same image as the original server.

Pay-per-Use Disks

Table 1 Detaching and reattaching of pay-per-use EVS disks

Original Use

Target Server

New Use

Supported

System disk

(It becomes a bootable disk after being detached.)

Attach to the same server

System disk

Data disk

Attach to another server

System disk

Data disk

Data disk

Attach to the same server

System disk

×

Data disk

Attach to another server

System disk

×

Data disk

Yearly/Monthly Disks

  • Yearly/monthly EVS disks purchased together with a yearly/monthly server belong to the same order and are in a binding relationship. After such EVS disks are detached, they cannot be re-attached to other servers.
    • You can detach such a system disk and then re-attach it to the same server as a system disk or data disk.
    • You can detach such a data disk and then re-attach it to the same server as a data disk.
  • Yearly/monthly EVS disks that are separately purchased can serve as data disks only. You can detach such a disk and then re-attach it to the same server or other servers as a data disk.