want to know more about single user mode

[sunnyy9]

i came across a thread where we can log in single user mode by acessing the interactive menu of grub..........
i m just curios wat is this single user mode and what is grub interactive menu?
if someone can just post the screenshot of it it will be good.........

[donnie3543]

When you boot the computer you can press tab in grub and put init 1 or just 1 in the line to boot into single user mode. This mode can be used for admin purposes but I have never needed it.

If your already booted into the os you will need to open the terminal and use the following:

$ sudo init 1

There are different runlevels in the os, if you want to know more about it just go to Wikipedia and search for the term "runlevel". I wouldn't recommend going into single user mode unless you know what you are doing though. Hope that helps.

[jpollard]

Single user mode is used for repair of some failure - such as the desctruction of the /etc/shadow password file.

Single user mode is an console interactive for root only. That means that usually, none of the disk mounts, other than root, may not be mounted, and root itself may be mounted read only (usually only occurs after a crash/power failure where the system is not shutdown gracefully, AND automatic repairs fail). By definition, only one user may be logged in (root).

There is no network, no general services (audio/USB/whatever). Using the root shell allows you to run most things (but not using a GUI), and is command line only. It can be used to install software, if the software is locally available (rpm/tarball/whatever). Sometimes (depending on the system) you cannot even compile things (Fedora doesn't have that restriction as it has nearly all software in the root filesystem).

Normally, when this single user account logs out (via control D or exit of the top level shell) the system will then attempt to come up in multiuser mode.

[sunnyy9]

thanks for your answers, it will help me to learn more about this os.........