Boot Linux Grub Into Single User Mode

by on April 19, 2006 · 30 comments· LAST UPDATED December 24, 2008

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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.

See also:

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{ 30 comments… read them below or add one }

1 sameer February 26, 2008 at 7:08 am

am using red hat 9.
user should not be allowed to change root password in single user mode,as it’s in SUSE.
i have already tried grub password.
i want some other method.
pls help me out.

Reply

2 Patrick July 20, 2009 at 1:45 am

i have tried the possible causes regarding the problem that i have encountered…..the username and passowrd has expired has been prompt when i logged in into my redhat ubuntu. can you please help me out.

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3 Rajdeep Basak July 29, 2009 at 7:49 pm

Hi folks,
Thank you so so much for all these informations, I really needed them badly.
Tahnks again
ENJOY

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4 Tiphaine September 24, 2009 at 2:11 pm

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?

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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

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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.

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7 zehez January 2, 2010 at 12:50 pm

Using “1″ also works

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

HI,

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

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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 …

Reply

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

How to make bootable usb drive

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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!

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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.

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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..

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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!

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

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

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16 Chris May 6, 2011 at 2:55 pm

MUST BE “S” or “single”. Screenshot above of “Single” is wrong.

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17 Sudhanshu June 13, 2011 at 9:41 am

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

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18 pENIS August 12, 2011 at 1:17 pm

Hello

Put ‘single’ in lowercase for this to work.

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19 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.

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20 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

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

Thanks for Info :D

Reply

22 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

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23 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 #

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24 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.

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25 Sajal November 23, 2012 at 6:23 am

Thanks to help me
i did Successfully

Reply

26 Amit shukla December 10, 2012 at 4:33 pm

Hi friends

i have encounterd a problem regarding my centOS .95
file system has been currepted plz help me to come out..

Regards
Amit shukla

Reply

27 hoohoo March 18, 2013 at 9:28 am

how to edit “/etc/default/grub” from grub menu from commandline (c) . as “sudo nano /etc/default/grub.” does not work. there

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28 avoc15082013 August 15, 2013 at 12:31 pm

This will help you.

[root@oc15082013 ~]# chage -l
Usage: chage [options] [LOGIN]

Options:
-d, –lastday LAST_DAY set date of last password change to LAST_DAY
-E, –expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE
-h, –help display this help message and exit
-I, –inactive INACTIVE set password inactive after expiration
to INACTIVE
-l, –list show account aging information
-m, –mindays MIN_DAYS set minimum number of days before password
change to MIN_DAYS
-M, –maxdays MAX_DAYS set maximim number of days before password
change to MAX_DAYS
-W, –warndays WARN_DAYS set expiration warning days to WARN_DAYS

[root@oc8327105564 ~]# chage -l root
Last password change : Aug 09, 2013
Password expires : Nov 07, 2013
Password inactive : never
Account expires : never
Minimum number of days between password change : 1
Maximum number of days between password change : 90
Number of days of warning before password expires : 7
[root@oc15082013 ~]#

Reply

29 Toronto guy December 4, 2013 at 5:02 am

thanks guys for the help, it worked …
I was able to boot my system after it was stuck at grub>

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30 alex July 1, 2014 at 9:18 am

change “Single” in kernel row ro to rw and add init=/bin/bash then press F10, then you will have root command line

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