This topic describes how to configure UUID in the fstab file to automatically mount the file system of data disks.

Overview of Practices

In the Linux system, if you want to automatically mount disks when the cloud server system starts, do not specify /dev/vdb1 in /etc/fstab because the sequential encoding of devices in the cloud may change when the cloud server stops or starts. For example, /dev/vdb1 may change to /dev/vdb2. We recommend that you use UUID to configure automatic disk mounting. The Universally Unique Identifier (UUID) of a disk is the universally unique string that the Linux system provides for disk partitions.

Configure UUID in the fstab file to automatically mount data disks in the following steps:

• Query the information of the disk partition.

• Configure the fstab file.

• Check whether the configuration takes effect.

Preparations Before Operation

The partition for the EVS mounted to the cloud server has been formatted. For more information, see Initializing Linux EVS.

Resource Planning

You must prepare the following resources before configuring UUID in the fstab file to automatically mount data disks.

Resource	Resource Description	Quantity	Link for Details
ECS	The operating system is "CentOS 7.6 64-bit"	1	ECS Billing
Elastic IP (EIP)	ECS must be bound to an elastic IP to download the installation package	1	EIP Billing
EVS	Data disk: 10 GB	2	EVS Billing

Creating Resources

• Create an elastic cloud server with the operating system image being CentOS 7.6 64 bit. For more information, see Creating ECS

• Create an elastic IP and bind it to the elastic cloud server. For more information, see Purchasing an EIP and Binding ECS Instance

• Purchase two 10 GB data disks and mount them to the elastic cloud server. For more information, see Creating EVS and Mounting EVS

After the preceding resources are created and the EVS partition is formatted, go to the next step to configure UUID in the fstab file to automatically mount data disks.

Operation Steps

Configure UUID in the fstab file to automatically mount data disks in the following three steps:

• Step 1: Query the information of the disk partition.

• Step 2: Configure the fstab file.

• Step 3: Check whether the configuration takes effect.

Step 1: Query the information of the disk partition

In the following steps, the operating system is CentOS 7.6 64-bit. The returned information is for reference only.

Run the blkid /dev/vdb1 command to query the UUID of disk partition /dev/vdb1 and type of the file system. The following information is returned:

Step 2: Configure the fstab file

Run the vi /etc/fstab command to open the fstab file using the VI editor. Type "i" to go to the editing mode, move the cursor to the end of the file, and press Enter to add the following content, as shown in the figure:
• In the UUID= field in the first column, enter the UUID you queried in the previous step.
• /mnt/sdc in the second column is the mount point.
• In the ext4 field in the third column, enter the type of the file system you queried in the previous step.
• The fourth column displays the parameters used when you mount the disk. In general, defaults are used.
• The fifth column enables you to determine whether to back up this file system. 0 indicates no backup. 1 indicates backup.
• The sixth column enables you to determine whether to check the priority of the file system. 0 indicates no check. To check the priority of the file system, set the file system in the root directory 1, and set other file systems in non-root directory to 2.
Press ESC , type ":wq", and press Enter . Save settings and exit the editor.

Step 3: Check whether the configuration takes effect.

To verify the automatic mounting function, unmount the mounted partition and run the umount /dev/vdb1 command, as shown in the figure:
Run mount- a to reload all the contents of the /etc/fstab file, as shown in the figure:
Run the mount |grep /mnt/sdc command to query the mount of the file system. The operations and returned information are shown in the following figure:

If the information shown in the figure is returned, the automatic disk mounting is successfully set.

Elastic Volume Service

Configuring UUID in the fstab File to automatically Mount Data Disks