Scenarios
A cloud disk is an expandable storage device on cloud. After a cloud disk is created, you can expand its storage capacity at any time without losing any data in it.
After expanding the cloud disk, you need to expand the partitions and file systems. You can allocate the capacity of the expanded part to an existing partition or format it into a new partition.
Note
MBR partition supports disk with a maximum capacity of 2 TB. When you partition disk with a capacity greater than 2 TB, we recommend that you create and attach a new data disk and use the GPT partition format to copy data.
Expanding Data Disks
If the cloud disk is a data disk, you can expand it using the following three methods.
Note
If multiple cloud disks of the same capacity and type are attached to the CVM, you can identify them using the method shown in Distinguishing data disks. Select a data disk and expand its capacity as instructed below.
Log in to the CVM console.
Locate the target CVM, and select More > Resource Adjustment > Expand System Disk under the Operation column.
Select the data disk to be expanded in the pop-up window, and click Next.
Select a new capacity, which must be greater than or equal to the current capacity, and click Next.
Read the notes and click Adjust Now.
Assign its expanded capacity to an existing partition, or format it into an independent new partition. Depending on the operating system of the CVM, see Extending Partitions and File Systems (Windows) or Determining the Expansion Method.
- Log in to the CBS console.
- Select More > Expand for the target cloud disk.
- Select a new capacity. It must be greater than or equal to the current capacity.
- Complete the payment.
- Assign its expanded capacity to an existing partition, or format it into an independent new partition. Depending on the operating system of the CVM, see Extending Partitions and File Systems (Windows) or Determining the Expansion Method.
You can use the ResizeDisk
API to expand the specified cloud disks. For more information, see ResizeDisk.
Expanding System Disks
- Log in to the CVM console. Locate the CVM on which you want to expand the system disk, and select More > Resource Adjustment > Expand System Disk under the Operation column.
- Select the system disk to be expanded in the pop-up window, and click Next.
- Select a new capacity, which must be greater than or equal to the current capacity, and click Next.
- Complete the capacity expansion by the following methods:
- Read the notes, select Agree to a forced shutdown, and click Adjust Now.
- After the expansion is completed on the console, check the cloudinit configuration for Linux instances or Windows instances according to the operating system of the CVM. Then expand partitions and file systems as needed.
Note
CVM supports online capacity expansion for cloud disk serving as system disk, i.e., non-stop capacity expansion. To use this feature, submit a ticket for application.
- Read the notes and click Adjust Now.
- Complete the capacity expansion in the console and refer to Logging in to Windows Instance Using RDP to expand partitions and file systems.
Operations
Distinguishing data disks
Check cloud disks according to the operating system of the CVM.
- Log in to a Linux instance.
- Run the following command to view the relationship between the elastic cloud disks and the device name.
ls -l /dev/disk/by-id
The following information will appear:

Note that disk-xxxx
is the ID of a cloud disk. You can use it to view cloud disk details on the CBS console.
- Log in to a Windows instance。
- Right click
, and select Run. - Enter
cmd
in the pop-up window and press Enter. - Run the following command to view the relationship between the elastic cloud disks and the device name.
wmic diskdrive get caption,deviceid,serialnumber
You can also run the following command.
wmic path win32_physicalmedia get SerialNumber,Tag
The following information will appear:

Note that
disk-xxxx
is the ID of a cloud disk. You can use it to view cloud disk details on the
CBS console.
Checking the cloudinit configuration
Check cloud disks according to the operating system of the CVM.
After the system disk is expanded, log in to the Linux instance and check whether the /etc/cloud/cloud.cfg
file contains the growpart
and resizefs
configuration items.
- If yes, ignore other operations.

- growpart: expands the partition to the disk size.
- resizefs: expands or adjusts the file system in the
/
partition to the partition size.
- If no, manually extend partitions and file systems (Linux) according to the operating system, and assign its extended capacity to an existing partition, or format it into an independent new partition.
After the system disk is expanded, log in to the Windows instance and check whether the ExtendVolumesPlugin
configuration item exists under plugin
in C:\Program Files\Cloudbase Solutions\Cloudbase-Init\conf\cloudbase-init.conf
.
- If yes, ignore other operations.
- If no, manually extend partitions and file systems (Windows) according to the operating system, and assign its extended capacity to an existing partition, or format it into an independent new partition.
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