All Products
Document Center

The "UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY." error occurs when the ECS instance fails to start

Last Updated: May 20, 2022

Problem description

The ECS instance operating system fails to start. The following error is returned when you use the management terminal to log on to the ECS instance:


If an output similar to the following one is displayed, Python is installed.


Certain conditions such as power-off can cause the ECS instance to be migrated to another backend machine. Memory data loss results in file system errors, such as invalid inode. A file system consistency check is performed when the operating system starts. If an error is detected, the system automatically fixes the error. However, if the following error occurs, the system does not automatically fix the error. The system stays on the error page and prompts you to manually run the fsck tool.

  • Abnormal shutdown causes memory data loss and therefore inode errors. Some invalid inode errors caused by abnormal shutdown may be removed during the automatic repair by the system.


Take note of the following items:

  • Before you perform high-risk operations such as modifying the specifications or data of an Alibaba Cloud instance, we recommend that you check the disaster recovery and fault tolerance capabilities of the instance to ensure data security.
  • Before you modify the specifications or data of an Alibaba Cloud instance, such as an Elastic Compute Service (ECS) instance or an ApsaraDB RDS instance, we recommend that you create snapshots or enable backups for the instance. For example, you can enable log backups for an ApsaraDB RDS instance.
  • If you have granted specific users the permissions on sensitive information, such as usernames and passwords, or submitted sensitive information in the Alibaba Cloud Management Console, we recommend that you modify the sensitive information at the earliest opportunity.

Different repair methods are required for different operating systems. Use one of the following methods depending on actual circumstances.

  • Emergency mode: If your operating system supports emergency mode, you can enter emergency mode and run the fsck tool to fix the file system.
    Note: The Ubuntu operating system supports emergency mode. For other systems, see relevant official documentation.
  • GRUB selection page: Take the following steps to fix the problem.
    Note: Different operating systems access GRUB in different ways. This example uses CentOS7. The actual steps may vary depending on your operating system.
    • On the GRUB selection page, select a kernel. Enter e.
    • Select the Kernel GRUB parameter to be modified and add the following parameters at the end:
      If an output similar to the following one is displayed, Python is installed.
    • Press Ctrl+X to start the operating system.

Applicable scope

  • Elastic Compute Service (ECS)