Can I Attach Multiple Disks to an ECS?

Yes. The ECSs created after the disk function upgrade can have up to 60 attached disks.

After you create an ECS, you can attach up to 60 disks to it.

**Table 1** Numbers of disks that can be attached to a newly created ECS
ECS Type	Maximum VBD Disks	Maximum SCSI Disks	Constraint
Xen (excluding D1 ECSs)	60	59	VBD disks + SCSI disks ≤ 60 (This constraint does not apply to local disks.) The number of local disks is determined based on the ECS flavor.
D1	60	59	VBD disks + SCSI disks + Local disks ≤ 60 The number of local disks is determined based on the ECS flavor.
KVM (excluding D2 and D3 ECSs)	24	59	VBD disks + SCSI disks ≤ 60 (This constraint does not apply to local disks.) The number of local disks is determined based on the ECS flavor.
D2 and D3	24	30	VBD disks + SCSI disks ≤ 54 (This constraint does not apply to local disks.) The number of local disks is determined based on the ECS flavor.

The system disk of an ECS is of VBD type. The maximum number of SCSI disks is 59.
For a D-series KVM ECS, its local disks use two SCSI controllers, indicating that 30 SCSI drive letters are used. A maximum of 30 SCSI disks can be attached to such an ECS.

The maximum number of disks that you can attach to an ECS that was created before the disk function upgrade remains unchanged, as shown in Table 2.

**Table 2** Numbers of disks that can be attached to an existing ECS
ECS Type	Maximum VBD Disks	Maximum SCSI Disks	Maximum Local Disks	Constraint
Xen	60	59	59	VBD disks + SCSI disks + Local disks ≤ 60
KVM	24	23	59	VBD disks + SCSI disks ≤ 24

To attach 60 disks to an exiting ECS, create the same ECS, modify its specifications, reinstall/change its OS, or migrate the ECS.

Log in to management console.
Under Computing, click Elastic Cloud Server.
Click the name of the target ECS. The page providing details about the ECS is displayed.
Click the Disks tab.
Check the number of disks that can be attached to the ECS to determine the total number of disks.
- If the total number of disks that can be attached is 24 (including the system disk), the ECS is created before the disk function upgrade.
- If the total number of disks that can be attached is 60 (including the system disk), the ECS is created after the disk function upgrade.