Operation Scenario
To guarantee correct disk recognition by the Linux system during file system mounting, please inspect and correctly set the fstab file disk identification method.
The file system table (fstab) is a configuration file in the Linux system that stores file system mounting information. Typically, the /etc/fstab
file supports the use of device names (such as /dev/vda1
) to identify file systems. However, device names may change due to the change in the actual operating environment after an image is imported, so there may be some problems using device names to identify file systems. To avoid these problems, you can change the file system identification method in the /etc/fstab
file to UUID. The UUID is a unique characteristic string that identifies a disk partition and won't be affected by the change in device names. Using a UUID as the fstab file disk identification can ensure that the system can still correctly mount the file system when the device name changes.
Setting the Fstab Disk Identification Method to UUID
Confirming the Current Configuration of Fstab
Run the following command to view the current configuration method.
If the output resembles the following one, with the first column beginning with UUID, it indicates that the current fstab is configured using the UUID method.
UUID=c0b9ecd8-f922-4e5d-bccb-83fbc94ad23b / ext4 defaults 1 1
If the output resembles the following one, with the first column beginning with the block device name (such as /dev/vda1
), it indicates that the current fstab is using a device name. You can refer to the subsequent operation to switch to the UUID method.
/dev/vda1 / ext4 defaults 1 1
Obtaining the UUID
To obtain the UUID of a partition, the blkid
command can be used. Running the blkid
command will display the detailed information of all the available partitions including the UUIDs. Run the following command in the terminal:
The output similar to the following one indicates that the associated UUID of the device /dev/vda1
is c0b9ecd8-f922-4e5d-bccb-83fbc94ad23b
.
/dev/vda1: UUID="c0b9ecd8-f922-4e5d-bccb-83fbc94ad23b" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="bcfcb5cb-01"
Modifying fstab
1. Backup the current /etc/fstab
file to the /home
directory.
2. Use the vi editor to open the /etc/fstab
file.
3. Edit the configurations beginning with device names in the fstab file. Change device names to the UUID=xxx
format. The content after UUID=
is the UUID value corresponding to the device returned by running the blkid
command.
/dev/vda1 / ext4 defaults 1 1
UUID=c0b9ecd8-f922-4e5d-bccb-83fbc94ad23b / ext4 defaults 1 1
4. Press Esc to enter :wq. Press Enter to save the configuration and exit the editor.
5. (Optional) Run the following command to ensure that the modification has been successfully saved.
If the following content is returned, it indicates the modification has been saved successfully.
UUID=c0b9ecd8-f922-4e5d-bccb-83fbc94ad23b / ext4 defaults 1 1
6. (Optional) Run the following command. If no errors are returned, it means that the configuration has been successfully performed in accordance with the UUID method.
7. (Optional) Delete the backup fstab file in the /home
directory.
If the modification to UUID identification failed, the system can be restored to the original state by restoring the fstab file.
sudo mv /home/fstab /etc/fstab
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