The Linux Helpline

Linux utilizes what is called "runlevels". A runlevel is a software configuration of the system that allows only a selected group of processes to exist. Init can run the system in one of eight runlevels. These runlevels are 0-6 and S or s. The system runs in only one of these runlevels at a time. Typically these runlevels are used for different purposes. Runlevels 0, 1, and 6 are reserved. For Redhat Linux version 6, the runlevels are: 0 - halt 1 - Single user mode 2 - Multiuser, without NFS (The same as 3, if you don't have networking) 3 - Full multiuser mode 4 - unused 5 - X11 6 - Reboot 1.       level 0 : to halt the system, it reboots the systems again and again after login in 2.       level1 :single user mode, this is a special mode in which only one use ie the super user mode in which limited syst...

1.       Bin: provides binary libraries ie. All the library files required for execution of a program. It also creates links for the various programs which are installed in the system. 2.        Boot: this directory contains the various boot related files for eg the the configurations of boot loaders like(GRUB and lilo),kernel files(that form the core of linux). 3.        Cdrom:this is a directory in which the cd rom is mounted. 4.        Dev: this directory contains the basic configuration files for devices and their respective drivers which are used when various devices are called by the system programs. 5.        etc : This is the most important directory in the linux file system hierarchy. It consist of all the files required for for a software to run ie all the source files whjch are required during execution are present here. It consi...

This could be easily done using single user mode of linux. 1.To boot into single user mode change any entry of grub that boots ubuntu 2. Go to the kernel line and add single at the end of it. 3. Now boot from it. 4. Once it boots to change root password Passwd root 5. Change password and enjoy