This topic describes the causes of and solutions to startup failures on an Elastic Compute Service (ECS) instance.
Problem description
The instance fails to start, and an error message similar to the following appears.
Causes
The /boot directory is missing key boot files, such as the kernel image
vmlinuzor the root file system (rootfs) imageinitramfs, which prevents the instance from starting properly.The /etc/os-release and /usr/lib/os-release files do not exist. This prevents the
systemdinitialization program from correctly detecting the operating system. As a result, the instance cannot start properly.
The following operations are verified on an Alibaba Cloud Linux 3.2 64-bit operating system. The operations may vary depending on the operating system. For more information, see the official documentation for your distribution.
Method 1
You can restore the system disk from a snapshot.
You can roll back a disk using a snapshot.
For more information, see Roll back a disk using a snapshot.
Method 2
The instance has started
You can use Secure Copy Protocol (SCP) or Object Storage Service (OSS) to copy the required startup files from another instance that uses the same image to the affected ECS instance.
The instance fails to start
You can copy and restore the startup files from another instance that uses the same image.
Find the missing files.
Create an ECS instance from the same image.
For more information, see Create an instance using a custom image.
Detach the system disk of the abnormal instance and record the disk ID.
For more information, see Detach a system disk.
Attach the detached system disk to the new ECS instance.
For more information, see Attach a data disk.
Copy the startup files to the attached system disk.
Reattach the repaired system disk to the original instance.