Tag Archives: Booting

Recovering root password under Linux with single user mode

It happens sometime that you can’t remember root password. On Linux, recovering root password can be done by booting Linux under a specific mode: single user mode.
This tutorial will show how to boot Linux in single user mode when using GRUB and finally how to change root password.
During normal usage, a Linux OS runs under runlevels between 2 and 5 which corresponds to various multi-user modes. Booting Linux under runlevel 1 will allow one to enter into a specific mode, single user mode. Under such a level, you directly get a root prompt. From there, changing root password is a piece of cake.
Some Linux distribution, such as Ubuntu for instance, offer a specific boot menu entry where it is stated “Recovery Mode” or “Single-User Mode“. If this is your case, selecting this menu entry will boot your machine into single user mode, you can carry on with the next part. If not, you might want to read this part.
Using GRUB, you can manually edit the proposed menu entry at boot time. To do so, when GRUB is presenting the menu list (you might need to press ESC first), follow those instructions:
– 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 e to edit this entry
– at the end of the line add the word: single
– press ESC to go back to the parent menu
– press b to boot this kernel
The kernel should be booting as usual (except for the graphical splash screen you might be used to), and you will finally get a root prompt (sh#).
Here we are, we have gained root access to the filesystem, let’s finally change the password.
As root, changing password does not ask for your old password, therefore running the command:
# passwd
will prompt you for your new password and will ask you to confirm it to make sure there is no typo.
That’s it, you can now reboot your box and gain root access again.

Auto Mount Drives at System Startup on Ubuntu

7 Replies

Ubuntu is capable of reading and writing files stored on Windows formatted partitions, but partitions must be ‘mounted’ before they can be accessed each time you start up the system. With these steps, you can auto mount the drives or partitions without the need to manually mount them for access.
Install Storage Device Manager if it has not been added.
– go to Applications (or Main Menu) > Ubuntu Software Center.
– enter pysdm in the Search Box.
– select Storage Device Manager, click the “Install” button.
– go to System > Administration > Storage Device Manager.
– extend the list of sda and select the sda you want to auto mount, click ‘OK’ to configure.
– click the “Assistant” button.
– uncheck “Mount file system in read only mode” and keep “The file system is mounted at boot time” checked.
– click the “Mount”, “Apply” then “Close” button, and restart the system.
In case you wish to remove the auto-mount of a certain drive or partition, you can similarly use Storage Device Manager to do the setting.

Note: If you need to identify disk partitions by label, paste ls /dev/disk/by-label -g in Terminal, or to view partition sizes and file systems, enter sudo fdisk -l. Disk Utility mentioned in “Name or Label a Partition” also gives you a glance of device numbers, partition types, sizes and labels.

Name or Label a Partition using Ubuntu

Leave a reply

Nautilus file manager shows the root directory as File System for your Ubuntu system partition. If you have other partitions (or volumes), it shows them as xx GB Filesystem if they’re not named or labelled.
Using Disk Utility is one of the effective ways to name a partition easily:
– go to System > Administration > Disk Utility
– select the item Hard Disk.
In the Volumes section, click a partition you want to label then:
– click “Edit Filesystem Label” (Note 1)
In the Label box, enter a name, e.g. Data-Disk, and click Apply.
The file manager should now show the partition label, such as Data-Disk, instead of xx GB Filesystem.

Note 1: If the option for “Edit Filesystem Label” is not shown, click “Unmount Volume” before hand. In case you can’t unmount a volume, try Storage Device Manager to unmount it. See Auto Mount Drives at System Startup.

Note 2: This tip is for naming a partition using Disk Utility, use other advanced features such as format, edit or delete partition with caution as they can delete data on your disk.