Help Center/ Elastic Cloud Server/ FAQs/ Disk Partition, Attachment, and Expansion/ What Should I Do If My Linux ECS Fails to Start Due to Incorrect /etc/fstab File Configuration?
Updated on 2025-08-06 GMT+08:00
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What Should I Do If My Linux ECS Fails to Start Due to Incorrect /etc/fstab File Configuration?

Symptom

For Linux ECSs, their automatic mounting of file systems is configured in the /etc/fstab file. If the automatic mounting information is incorrectly configured or unavailable, the ECS OS may fail to start after the system is restarted.

For details, see /etc/fstab File Introduction.

Possible Causes

  • The /etc/fstab file was not modified before the disk is detached or reinitialized. As a result, the /etc/fstab file contains unnecessary automatic mounting information of file systems.
  • The device name or UUID of a file system is incorrectly configured.
  • The file type of a file system is incorrectly configured.
  • The mount parameters are incorrect.

Solution

  1. Log in to the ECS. For details, see Login Overview (Linux).
  2. Run the following command to back up the /etc/fstab file before modifying it:

    cp /etc/fstab /etc/fstab.bak

  3. Run the following command to check the content of the /etc/fstab file and ensure that the mount path, device name, or UUID is correct:

    cat /etc/fstab

    Figure 1 Check results
    1. Check the mount point.

      Check that each mount point (for example, /mnt/data) exists and has the correct permissions and owner.

    2. Check the device or UUID.

      You are advised to mount partitions using the UUID to prevent errors in the fstab file caused by device name changes. These changes may occur when an ECS is restarted after specifications are modified or disks mounted or unmounted.

      Run the following command to obtain the device UUID and ensure that the device name (for example, /dev/vda1) or UUID exists and is correct:

      blkid

      Figure 2 Obtaining the device UUID
    3. Check the mount options.

      Check whether the mount option of each mount partition is correct, for example, defaults and rw.

    4. Check the mount status.

      Run the following command to check whether all file systems are correctly mounted:

      df -h

      Figure 3 Check results

      Compare the /etc/fstab file content with the mount point details in the command output, and delete unnecessary configuration lines from the /etc/fstab file.

  1. Run the following command to test the mount result:

    mount -a

    This command automatically mounts the file system based on the configuration in the /etc/fstab file.

    • If no error is displayed, the /etc/fstab file is correctly configured. No further action is required.
    • If an error is displayed, use a text editor (such as vi or nano) to edit the /etc/fstab file based on the error information, and save the modified file.
  1. If the /etc/fstab file is modified, run the following command to restart the system to apply the modification.

    reboot

/etc/fstab File Introduction

Table 1 lists each field in the /etc/fstab file.

Figure 4 /etc/fstab file
Table 1 /etc/fstab file fields

Field

Description

file system

UUID of the file system of the partition to be mounted. For example, UUID=xxxx-xxxx.

dir

Mount point.

type

File system type of the partition to be mounted, for example, ext4 or xfs.

options

Mount parameter. The defaults parameter is generally used. If multiple parameters are required, separate them with commas (,).

Table 2 lists common mount parameters.

dump

Whether a file system is backed up with dump.

  • 0: The file system is not backed up.
  • 1: The file system is backed up.

pass

Determines the check sequence of the file systems with fsck. A smaller value indicates a higher check priority.

Rule:

  • 1: Root file system
  • 2 or a larger value: Other file systems
  • 0: No check is required.
Table 2 Mount parameters

Mount Option

Description

defaults

Uses the default mount parameters of file systems. Separate multiple parameters with commas (,).

For example, the default parameters of the ext4 file type are rw,suid,dev,exec,auto,nouser,async.

rw

Mounts a file system as read/write.

ro

Mounts a file system as read-only.

auto

Automatically mounts at startup or when the mount -a command is executed.

noauto

Requires manual mounting using commands.

suid

Allows the suid operation and setting of sgid bits. Generally, this parameter is used to temporarily elevate the permissions of common users when they run special tasks.

nosuid

Prevents the suid operation and sgid bits.

dev

Parses the block device on the file system.

nodev

Does not parse the block device on the file system.

exec

Allows the execution of executable files on mount points.

noexec

Prevents the execution of executable files on mount points.

nouser

Only allows the root user to mount file systems.

async

Asynchronous I/O

sync

Synchronous I/O

nofail

If the device does not exist when you start the ECS, the device is ignored.