Linux, DevOps, Middleware and Cloud

How to reset forgotten root password in Linux? The root password for the Linux system can be reset by booting it into the Single User mode which is also termed as Emergency mode or more popularly known as Rescue mode. If the boot loader installed on your Linux system is GRUB, then please follow the below listed steps to reset the root password. Select the line which specifies the kernel to be loaded. Press the ‘e’ key to edit the entry. Choose second line (the line starting with the word kernel). Press the ‘e’ key again to edit kernel entry Append the letter ‘S’ or word ’single’ to the end of the line. Press the [ENTER] key Press the ‘b’ key to boot the Linux kernel into single user mode After the booting process completes, mount the ‘/’ and ‘proc’ partitions using the below listed commands. # mount -t proc proc /proc # mount -o remount,rw / Issue the 'passwd' command to change the root password. Finally, reboot the system employing the below commands. # sync # re...

Run Levels and inittab – RHEL Now that we have already seen the boot sequence and GRUB file for linux, lets now check what is run level and one of the important file /etc/inittab which is used during booting linux. Run Level Operating system like linux has several services that are running. Each service will provide some functionality to OS. Example ftp service will allow other machine to FTP from your machine. Similarly network service will allow networking functionality. But keeping all the services running while working on only few serivce will impact performance. Some times administrator does not need all the services and just need few services for working. For this kind of situation, linux provides different runlevel. Each run level has some specific set of services running. Example if you start your linux in run level 1, some specific set of services will get started but not all. If you boot linux in run level 2 some more services will get started over and above services ...