You can set the kernel parameter kernel.unknown_nmi_panic of a Linux ECS instance system to 0 to resolve the instance restart issue caused by unexpected kernel panic.

Causes

The kernel parameter kernel.unknown_nmi_panic controls the kernel's behavior when an unknown non-maskable interrupt is encountered. On most Linux distributions, the default value of this parameter is 0, which means unknown non-maskable interrupts are ignored. If the value of kernel.unknown_nmi_panic is adjusted for any reason, the kernel may trigger a panic upon receiving an unknown non-maskable interrupt, causing the instance to restart.

kernel.unknown_nmi_panic = 1: The kernel will consider a system error when encountering unknown non-maskable interrupts and will trigger a kernel panic, causing unexpected instance restarts or business interruptions.

kernel.unknown_nmi_panic = 0: Ignore the issue without further processing, maintaining the current status of the instance to continue running.

Procedure

Configure the kernel.unknown_nmi_panic argument (permanent)

Configure the kernel.unknown_nmi_panic argument (temporary)

Log in to the target instance. For operation details, refer to Logging in to Linux instances.

Execute the following command to check whether the kernel configuration related to the kernel parameter kernel.unknown_nmi_panic exists.

grep 'kernel.unknown_nmi_panic' /etc/sysctl.conf /etc/sysctl.d/*.conf

If there is a related kernel configuration, only retain /etc/sysctl.conf file's kernel.unknown_nmi_panic = 0 entry.

tip

If the /etc/sysctl.conf file contains extra kernel configurations, it is recommended to use #to add comments.

If no such configuration exists, add kernel.unknown_nmi_panic = 0 to the end of the /etc/sysctl.conf file.

Execute the following command to make the configuration take effect.

sudo sysctl -p

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