A short experiment with Transparent Huge Pages (THP) on Linux

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Introduction of THP

A typical page in Linux memory management system is 4KB. To enhance the efficiency of allocating large amount of memory pages, the OS could make use of huge memory pages. Instead of using 4KB as a page, the OS could allocate a bigger block of page size in 2MB or 1GB. To use huge memory pages, the OS need to be configured so that the memory is preserved or allocated. Refer to the …

SSH public key authentication could bypass your security (PAM) policy

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Even after using Linux for years, you would always learn something new everyday. In this short article, I would talk about how SSH public key authentication could bypass security policy.

Let's start with pluggable authentication module (PAM). By using Linux PAM, the system could use modules to enhance the security of a system. For example, PAM could setup security policy that a password has to meet certain length and complexity. Another use case of the PAM …