How to reset a root password: Difference between revisions

Latest revision as of 18:20, 15 August 2015

This page is outdated and needs to be verified against current releases of Fedora.

Setting up a root password is a mandatory part of a Fedora installation. If you forget or otherwise lose your root password, there are procedures to reset it.

If you have set a password for your boot loader, refer to this section.
If you want to reset the boot loader password, refer to these instructions.
If none of these scenarios apply to you, proceed to the next section.

Fedora uses targets to determine the services being run when you start your system. Run level 1 can be used as a rescue mode. Booting Linux under run level 1, which is also called single user mode, will display a root prompt on bootup, from which you can reset the root password.

Entering Rescue Mode

Using GRUB2

GRUB2 has been the default boot loader since Fedora 16.

While booting the system the GRUB2 menu will be displayed, to boot the system using bash follow these steps:

Use the arrow keys to select the boot entry you want to edit
Press e to start editing that entry
Use the arrow keys to go to the line that starts with linux or linux16
- If you have a UEFI system it's the line that starts with linuxefi
Go the the end of that line add a space then rw then another space and init=/bin/bash
- If your disk is encrypted, you may need to add plymouth.enable=0 as well
Press Ctrl-x or F10 to boot that entry

Encrypted partitions
Whichever GRUB version your system has, if you have an encrypted partition, you are prompted for the pass phrase before mounting the filesystems. If have more than one encrypted partition and they all share a global pass phrase, select the option for global pass phrase. Otherwise, enter the pass phrase separately for each partition.

Changing root password

As root, changing password does not ask for your old password. Run the command:

# passwd

Enter your new root password twice. Congratulations! You now have now reset your root password.

To make sure that selinux context of file which were now modified is restored properly after reboot, run:

# touch /.autorelabel

You can than reboot the machine with

# /sbin/reboot -f

Reset Password Using a Fedora CD/DVD

Usage cases
This method should work to reset the root password if the boot loader is password protected. Or if you have a Fedora 19 (or newer) installation where booting to the rescue mode (which now invokes /sbin/sulogin) will ask you for the root password to proceed.

Using any of the Fedora Live Media

Boot the Live installation media
After it finishes booting and starts the live session, open a terminal and switch to root (using su, it won't ask for a password)
Create a directory where you can mount the filesystem of your installation:

mkdir /mnt/sysimage

Mount the filesystem of your installation (/dev/sda1 is just an example, be sure to fill in the actual device node of your installation root / partition):

mount /dev/sda1 /mnt/sysimage

chroot to your installation:

chroot /mnt/sysimage/

Change the root password:

passwd

Exit from the chroot:

exit

That's it, simply reboot your system and then boot the installation from the HDD as usual.

Reset Password When BIOS is Password Protected

If you cannot enter rescue mode because you forgot the BIOS password required to select an alternate boot device, you have three options:

Refer to your computer's documentation for instructions on resetting the BIOS password in CMOS memory, usually by moving a physical jumper.
Physically change the boot order.
Temporarily move the system hard disk to another machine, and follow the procedures above to reset the root password.

@@ Line 1: / Line 1: @@
+{{Admon/warning|| This page is outdated and needs to be verified against current releases of Fedora.}}
 Setting up a root password is a mandatory part of a Fedora installation. If you forget or otherwise lose your root password, there are procedures to reset it.
-* If you have set a password for your boot loader, refer to [[#bootloader-protected | this section]].
+* If you have set a password for your boot loader, refer to [[#using-installation-cd-dvd | this section]].
 * If you want to reset the boot loader password, refer to [[Reset_Bootloader_Password | these instructions]].
 * If none of these scenarios apply to you, proceed to [[#Entering_Rescue_Mode | the next section]].
-Fedora uses ''run levels'' to determine the services being run when you start your system. Run level 1 can be used as a rescue mode. Booting Linux under run level 1, which is also called ''single user mode'', will display a root prompt on bootup, from which you can reset the root password.
+Fedora uses ''targets'' to determine the services being run when you start your system. Run level 1 can be used as a rescue mode. Booting Linux under run level 1, which is also called ''single user mode'', will display a root prompt on bootup, from which you can reset the root password.
 == Entering Rescue Mode ==
-=== Using GRUB legacy ===
-{{Admon/note||GRUB legacy was the default boot loader up until Fedora 15.}}
-While your system is starting up, hold down the ''Ctrl'' key or ''Esc'' to see the boot loader menu. After you see the menu:
-* Use the arrows to select the boot entry you want to modify.
-* Press ''e'' to edit the entry.
-* Use the arrows to go to kernel line.
-* Press ''a'' or ''e'' to append this entry.
-* At the end of the line add the word ''single'' or the number ''1''.
-* Press ''Enter'' to accept the changes.
-* Press ''b'' to boot this kernel.
-A series of text messages scrolls by and after a short time, a root prompt appears awaiting your commands (#).
 === Using GRUB2 ===
 {{Admon/note||GRUB2 has been the default boot loader since Fedora 16.}}
-While booting the system the GRUB2 menu will be displayed, to boot into the rescue mode follow these steps:
+While booting the system the GRUB2 menu will be displayed, to boot the system using bash follow these steps:
 * Use the arrow keys to select the boot entry you want to edit
 * Press '''e''' to start editing that entry
-* Use the arrow keys to go to the line that start with '''linux'''
+* Use the arrow keys to go to the line that starts with '''linux''' or '''linux16'''
-* Go the the end of that line (by pressing '''End''') add a space then the word '''single''' or the number '''1'''
+** If you have a UEFI system it's the line that starts with '''linuxefi'''
+* Go the the end of that line add a space then '''rw''' then another space and '''init=/bin/bash'''
+** If your disk is encrypted, you may need to add '''plymouth.enable=0''' as well
 * Press '''Ctrl-x''' or '''F10''' to boot that entry
-{{Admon/note|Rescue Mode changes|This method should work to change the root passwords up until Fedora 18, i.e. after the system finishes booting you would get a root prompt (#) which you can use to change the root password. However Due to a change in systemd - this change was in effect since Fedora 19 - booting to the rescue mode (single user mode) will prompt you to enter the root password which obviously means you can't use this method to reset the root password.}}
+{{admon/note | Encrypted partitions | Whichever GRUB version your system has, if you have an encrypted partition, you are prompted for the pass phrase before mounting the filesystems. If have more than one encrypted partition and they all share a global pass phrase, select the option for global pass phrase. Otherwise, enter the pass phrase separately for each partition.}}
-{{admon/note | Encrypted partitions | Which ever GRUB version your system has, if you have an encrypted partition, you are prompted for the pass phrase before mounting the filesystems. If have more than one encrypted partition and they all share a global pass phrase, select the option for global pass phrase. Otherwise, enter the pass phrase separately for each partition.}}
 == Changing root password ==
@@ Line 39: / Line 30: @@
 <pre># passwd</pre>
-Enter your new root password twice. Congratulations! You now have now reset your root password. You can type reboot and press enter to restart your system.
+Enter your new root password twice. Congratulations! You now have now reset your root password.
-{{Anchor|bootloader-protected}}
+To make sure that selinux context of file which were now modified is restored properly after reboot, run:
-== Reset Password When Boot Loader is Password Protected ==
+<pre># touch /.autorelabel</pre>
-<ol>
+You can than reboot the machine with
-<li>Boot from the install or rescue CD/DVD.</li>
-<li>Select "Rescue installed system."</li>
-<li>Answer the prompts for language and keyboard.  Starting the network is optional and not needed.</li>
-<li>Let the rescue mode mount your file systems in the read/write mode.</li>
-<li>Hit ''Enter'' to get the shell prompt.</li>
-<li>At the prompt, enter the following commands.  Do not enter any ''#'' mark or the text following it.  These comments are shown for explanatory purposes only.
-<pre>chroot /mnt/sysimage   # Change to your disk file system
-passwd                 # Change the root password
-exit                   # Exit the chroot environment
-exit                   # Exit the rescue mode</pre></li>
-</ol>
-The system now unmounts the file systems and reboots.
+<pre># /sbin/reboot -f</pre>
+{{Anchor|using-installation-cd-dvd}}
+== Reset Password Using a Fedora CD/DVD ==
+{{Admon/note|Usage cases|This method should work to reset the root password if the boot loader is password protected. Or if you have a Fedora 19 (or newer) installation where booting to the rescue mode (which now invokes /sbin/sulogin) will ask you for the root password to proceed.}}
+=== Using any of the Fedora Live Media ===
+* Boot the Live installation media
+* After it finishes booting and starts the live session, open a terminal and switch to root (using <code>su</code>, it won't ask for a password)
+* Create a directory where you can mount the filesystem of your installation:
+<code>mkdir /mnt/sysimage</code>
+* Mount the filesystem of your installation (/dev/sda1 is just an example, be sure to fill in the actual device node of your installation root '''/''' partition):
+<code>mount /dev/sda1 /mnt/sysimage</code>
+* chroot to your installation:
+<code>chroot /mnt/sysimage/</code>
+* Change the root password:
+<code>passwd</code>
+* Exit from the chroot:
+<code>exit</code>
+That's it, simply reboot your system and then boot the installation from the HDD as usual.
 == Reset Password When BIOS is Password Protected ==
@@ Line 65: / Line 66: @@
 * Physically change the boot order.
 * Temporarily move the system hard disk to another machine, and follow the procedures above to reset the root password.
+[[Category:How_to]]

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