Attaching a Shared Disk
Independently purchased EVS disks are data disks. In the disk list, the function of such disks is displayed as Data disk, and the status is displayed as Available. In this case, you need to attach the data disks to servers for use.
This section describes how to attach a shared disk.
If your disk cannot be attached to a server, see Why My EVS Disk Cannot Be Attached to a Server?
- A shared disk can be attached to a maximum of 16 servers. These servers and the shared disk must be in the same AZ within a region.
- If a shared disk is in the In-use state, ensure that the maximum number of servers that the disk can be attached to has not been reached.
- All the servers of a shared disk must run either Windows or Linux no matter the disk is attached to them in a batch or individually.
For example, if you attach a shared disk to multiple Windows servers in a batch and then detach it from all its servers, the disk cannot be attached to Linux servers later. This is because Windows and Linux support different file systems and cannot identify the original file system on the disk. Improper operations may damage the original file system.
- A shared disk can only be used as a data disk. It cannot be used as a system disk.
Attaching the Disk on the EVS Console
- Log in to the management console.
- Under Storage, click Elastic Volume Service.
The disk list page is displayed.
- Locate the target disk in the list and click Attach.
Shared disks support batch attachment so that you can attach a shared disk to multiple servers at a time. The left area in the Attach Disk dialog box shows the server list. After you select the target servers, the selected servers will be displayed in the right area.
- Select the target servers and then select a device name from the drop-down list for each server you selected. Ensure that the disk and servers are in the same AZ.
One device name can be attached with one disk only. If a device name has been used, it will no longer be displayed in the drop-down list and cannot be selected.
- Click OK. A dialog box is displayed, showing "The attaching process is NOT completed yet. You must initialize the disk before using it".
- 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 servers. When the disk status changes to In-use, the disk is successfully attached.
If you simply attach a shared disk to multiple servers, files cannot be shared between the servers as shared disks do not have the cluster capability. Therefore, build a shared file system or deploy a cluster management system to share files between servers.
Attaching the Disk on the ECS Console
- Log in to the management console.
- Click in the upper left corner and select the desired region and project.
- Under Computing, click Elastic Cloud Server.
- In the search box above the upper right corner of the ECS list, enter the ECS name, IP address, or ID for search.
- Click the name of the target ECS.
The page providing details about the ECS is displayed.
- Click the Disks tab. Then, click Attach Disk.
The Attach Disk page is displayed.
- Select the target disk and set the device name as prompted.Device names are as follows:
- For Xen ECSs, you can specify the device name of a disk, such as /dev/sdb.
- For KVM ECSs, you can specify a disk as a system disk or data disk but cannot specify a device name for the disk.
- If no EVS disks are available, click Create Disk in the lower part of the list.
- For details about restrictions on attaching a disk, see What Are the Restrictions on Attaching an EVS Disk to an ECS?
- Click OK.
After the disk is attached, you can view the information about it on the Disks tab.