# Why Does the Disk Attachment of a Linux ECS Fail After I Modify the ECS Specifications?

#### Scenarios

After you modify specifications of a Linux ECS, disk attachment may fail. Therefore, you need to check the disk attachment after you modify the specifications.

#### Procedure

1. Log in to the ECS as user root.
2. Run the following command to view the disks attached before specifications modification:

   fdisk -l | grep 'Disk /dev/'

   Figure 1 Viewing disks attached before specifications modification

   As shown in Figure 1, the ECS has three disks attached: /dev/vda, /dev/vdb, and /dev/vdc.

3. Run the following command to view disks attached after specifications modification:

   df -h| grep '/dev/'

   Figure 2 Viewing disks attached after specifications modification

   As shown in Figure 2, only one disk /dev/vda is attached to the ECS.

4. Check whether the number of disks obtained in step 3 is the same as that obtained in step 2.
   - If the numbers are the same, the disk attachment is successful. No further action is required.
   - If the numbers are different, the disk attachment failed. In this case, go to step 5.
5. Run the mount command to attach the affected disks.

   For example, run the following command:

   mount /dev/vbd1 /mnt/vbd1

   In the preceding command, /dev/vbd1 is the disk to be attached, and /mnt/vbd1 is the path for disk attachment.

   Ensure that /mnt/vbd1 is empty. Otherwise, the attachment will fail.

6. Run the following commands to check whether the numbers of disks before and after specifications modification are the same:

   fdisk -l | grep 'Disk /dev/'

   df -h| grep '/dev/'

   - If the numbers are the same, no further action is required.
   - If the numbers are different, contact customer service.
   Figure 3 Checking the number of disks attached

   As shown in Figure 3, the numbers of disks before and after specifications modification are the same. The disks are /dev/vda, /dev/vdb, and /dev/vdc.

Parent topic: ECS Management