Boot Linux Grub Into Single User Mode

by nixCraft on April 19, 2006 · 26 comments· LAST UPDATED December 24, 2008

Q. How do I boot a Linux system into single user mode?

A. Single user mode is useful to fix some system problem. Following are steps you need to use to boot Grub boot loader into single user mode.

Procedure: Boot Linux Grub Boot Loader into single user mode

(1) At grub boot screen (after restart)

(2) Select the kernel

(3) Press the e key to edit the entry

(4) Select second line (the line starting with the word kernel)

(5) Press the e key to edit kernel entry so that you can append single user mode

(6) Append the letter S (or word Single) to the end of the (kernel) line

(7) Press ENTER key

(8) Now press the b key to boot the Linux kernel into single user mode

(9) When prompted give root password and you be allowed to login into single user mode.

Hi,
I have a red hat entreprise 5. A technician change the motherboard of computer. When I restart, the computer does not find the etho eth1 and I decide to pass by single user mode. But when i make step 5, i don’t have the good line and I can’t modify the line. How must i make ? does this problem come from other hardware probleme?

5 4 ever love yours November 15, 2009 at 7:12 pm

Hi friends
Thank you for you help.
This is my problem:
I can follow this instructions up to step 5
After that I am stuck. for example:
The inf guide on this screen is different from my screen
my GNU grub version is 0.97 (640k lower/1037859k upper memory
When it comes to edit the kernel and add the letter ‘S’, I dont have that option, so I dont know what else to do. Plese tell me what is the next step. I have not use that computer in months , because of this problem. Thank you

6 Etienne Pouliot December 18, 2009 at 4:42 pm

With GRUB, using the keywork “Single” does not work, it has to be lowercase : “single”.

Using only “S” also works.

7 zehez January 2, 2010 at 12:50 pm

Using “1″ also works

8 prabir Man Dangol August 27, 2010 at 11:09 am

HI,

Thank You very very much. I really needed badly. Thanks.

9 Zain October 9, 2010 at 6:29 pm

Hi ,
I have a computer in the company and we are four use this computer with four accounts.
I have the root password .. By using Single User Mode the others are able to change the root password …!!
It’s a big problem … I need away to prevent the Single User Mode …

10 prabir Man Dangol October 25, 2010 at 6:12 am

How to make bootable usb drive

11 laura November 7, 2010 at 5:56 am

Hi, i REALLY need help! I have a dell mini linux/ubuntu 8.04 version laptop with only one account which i forgot the password to. I was working on my setup options trying to get a new password and changed the system and HDD passwords. When i said ok my computer wouldnt boot and it prompted me for the passwords i enter in for the HDD/system ones. Now im stuck in grub mode and just wanna get back to my normal set up. Im sooooo confused. Help would be GREATLY appreciated thankyou! (btw: im getting a message saying kernal must be booted before i can boot my computer. How could i go about booting kernel?) thankyou!

12 Anonymous December 5, 2010 at 11:05 pm

you can set grub password and the password for the cmos. make sure the chasis is locked.

13 Meghraj Paudel February 28, 2011 at 8:22 am: hey when i restart the system then it stop to the following line..then i can’t cross over the step…
GNU Grub version 0.97
[Minimal BASH-like line editing is supported. For the first word, tab lists possible command completiions. Anywhere else TAB lists the possible completions of a device/filename]
grub >
plz how to cross over from here…..hope u all suggest me..
Reply

14 baariu martin March 9, 2011 at 11:31 am

i have followed the whole procedure but i don’t know what to do when i get the place asking for root password or an option of Ctrl-D to continue.
how do i bypass this since i dont remember my root password?
pls help!

15 Charles Banda March 19, 2011 at 4:47 pm

This is useful information can anyone send me this type of information in details

16 Sudhanshu June 13, 2011 at 9:41 am

I have also stuck exactly where Baariu Martin is.. Kindly help with more info.. Thanks :)

17 pENIS August 12, 2011 at 1:17 pm

Hello

Put ‘single’ in lowercase for this to work.

18 steven October 10, 2011 at 8:54 pm

I have ubuntu 8.04 and it is not allowing me to enter the single user mode. I have used the option e for the same and entered single at the end of the line but it does not work please let me know what should i do and what option should i use.

19 S.Muthu March 19, 2012 at 5:50 am

There are two hard disk create 1+0 raid and OS has been failed . how to retrieve data in the hard disk . OS is in separate partition and data in separate partition. Pls help it out

20 Yaser Gumilar July 11, 2012 at 6:40 am

Thanks for Info :D

21 dipmala September 27, 2012 at 11:46 am

Hi,

I am working on Solaris 10 , somehow the project file in /etc directory got edited or deleted now i am not able to login to the servers.
Can anyone suggest the solution..for this ..ASAP

22 Pas September 30, 2012 at 4:42 pm

Apply power.
When prompted hit any key in 3 seconds, this brings up GRUB
Type ‘a’ to get to append mode (modify kernel arguments), then type:
1
boot 1

You will come up to single user prompt #

23 Anil November 12, 2012 at 6:51 am

I am in real trouble when I reboot I don’t see a grup prompt to get into the single user mode. All that I see is some options such as F2 for setup and several other F options. I tried entering into each of these but never got anything that will let me enter single user mode. I am completely lost. Sorry for these novice rants. I am using RH 6.2 enterprise version. Any help will be greatly appreciated.

24 Sajal November 23, 2012 at 6:23 am