How to create customized bootable ISO image in RHEL/CentOS 7

I have written separate articles with detailed steps to create a user with encrypted password using kickstart file, or to perform interactive installation using kickstart file and with the steps to save the %pre installation logs as unless you save them, the pre installation logs would be deleted once the installation is successful. For the … Read more

How to Fix “Informational Exchange message must be encrypted”

This is the error you might get while configuring Openswan. As I received this error when I was configuring openswan to connect my sonicwall vpn. Error: #1: Informational Exchange message must be encrypted Solution: Make sure you have set these parameters in your Sonicwall  IKE (Phase 1) Proposal DH Group: Group 5 (not 2) Encryption: … Read more

Linux Kernel boot time Optimization

Linux Kernel boot time Optimization

Present state of Linux kernel booting process itself is highly optimized. I mean that there is no major deficiency in kernel loading architecture (as it is mostly serialized/linear) and little/no can be changed.  startup assembly code (setting up clk,cpu and soc registers) ->  detect memory layout, detect display, setup mmu, setup interrupt  table, enable paging … Read more