Recovering the GRUB 2 Boot Loader by cgermany77
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Category Archives: linux boot
How to correctly configure and use the Windows Network on Ubuntu 10.04 LTS
At the beginning it appeared as a no-solved mystery because in all the many posts I read, there were no effective solutions. On my Ubuntu 10.04 LTS I was no able to use the external hard disk I had connected to the LAN and every time I tried to mount it I only received this message: Unable to mount location – Failed to retrieve share list from server
In few words it was not possible to use the Windows Network and all the people with the same problem (which is specific for the Ubuntu 10.04) suggested to reconfigure Samba but all the configuration and scripts I tried were no effective to let me use the external hard disk.
At the end I found someone who talked about a possible firewall misconfiguration and I tried in many ways to bypass the situation using ufw commands and opening ports and services over the LAN:
$ sudo ufw status
[sudo] password for *****:
Status: active
To Action From
– —— —-
135,139,445/tcp ALLOW Anywhere (log)
137,138/udp ALLOW Anywhere (log)
Samba ALLOW Anywhere
192.168.0.3 Samba ALLOW 10.0.0.0/8
10.0.0.0/8 ALLOW 192.168.0.3 Samba
Unfortunately, every new permission I granted to Samba on my Firewall was not a real solution but when I tried to stop the Firewall (System –> Administration –> Firewall Configuration) using the default firewall manager, Ubuntu was able to find and work on the external hard disk.
For this reason I made some tests and found this solution:
1 – enter your router settings and find the list of the attached device
2 – find the name and the MAC address of the LAN device you want to connect to your PC
3 – find the menu for the Lan Setup and add an Address Reservation for the above device. Now you are sure that the router will always assign the same address to the device
4 – back to Ubuntu, install and launch Firestarter (for some incomprehensible reasons the default firewall manager is not able to create rules for Samba services and ports)
5 – on Firestarter, go to Preferences —> Policy Editor and click on “Apply policy changes immediately”
6 – try to connect again to Windows Network, obviously (sic) it will not work but then go to Firestarter —> Events and you will notice that the last line is the “missing” external disk which has an “unknown” service
7 – right-click the mouse on this line and “Allow connections from source”. Now the external hard disk is visible from Ubuntu 10.04 LTS and it is possible to work on it!
8 – to be sure that your LAN device will be rightly connected to Ubuntu 10.04 every time you boot up it: go to System –> Preferences –> Startup Applications
9 – add a new Firestarter rule typing the following command: sudo firestarter
That’s all! I hope you can find this post useful!
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. 
Damn Small Linux 4.2.5: the new updated version!
Today, in our Linux Page (in Spanish) we have posted a review about the new version (4.2.5) of Damn Small Linux. Damn Small Linux is one of our favourite distribution due to its capability to run on very old PC as 386/486/Pentium with very few hardware resources. This version has updated some features as Monkey Webserver 0.9.2 and is incredibly stable (as the previous ones, I must say). According to distrowatch.com, in the last 12 months Damn Small Linux has been the 10th most downloaded (and consequently used) Linux version also because, with no costs, many people are converting old Windows based machines to new up-to-date computers. Anyway, Damn Small Linux is based on Knoppix but is smaller and contains many improvements. Last but not least, I would like to focus your attention on the five different subversions available:
- dsl.iso is the standard isolinux version
- slinux.iso uses syslinux instead of isolinux (for very old PC’s)
- vmx.zip can be run in VMware Player
- embedded.zip contains QUEMU for running inside Windows
- frugal_lite.sh is the network install script and requires tomsrtbt linux: http://www.toms.net/rb/.
Lubi: the Linux based Ubuntu Installer
Lubi is a useful tool for all people who like to experiment different Linux OS on their PCs. In particular Lubi has been thought to let you install Ubuntu in just few clicks and without risking annoying “secondary effects” on your computer. In our Linux Page (in Spanish) we have posted a small but effective review with all the necessary links to the Lubi project and we have also listed all the Linux OS (PCLinuxOS 2007 32-bit, openSUSE 10.2 32-bit, Gentoo 2007.0 32-bit, etc..) already tested for a safe -Lubi- use. We strongly recommend Lubi for all users who want to deeply test Ubuntu (and its features) without starting from the Live CD.
Wubi: one of the best Ubuntu installers for Windows users.
Today, in our Linux page we have posted a brief review about Wubi: a simple and effective Ubuntu installer for Windows users. With just few clicks you can easily install Ubuntu without modifying the partitions on your pc (for this reason there are no -or very low- risks of “fatal errors” for your computer). All the Ubuntu files are stored in just a single folder so it is very simple to uninstall Ubuntu if you decide not to use it anymore. In few words, Wubi allows Linux beginners to try all the positive features of Ubuntu without risking undesirable secondary effects. Recommended!
Ubuntu 7.04: a complete Linux on a USB PenDrive
Today, in our Linux Page, we want talk again about bootable Linux on pendrives. This time we discovered that the guys from http://pendrivelinux.com/ released a new USB portable Linux: Ubuntu 6.10. We tried to use Ubuntu 7.04 instead 6.10 and… it works (in our test: Windows installation on 1GB pendrive)! As for Knoppix 5.1.0 (see our post on January 26, 2007) also this portable version of Ubuntu 7.04 is easy to be installed on a USB key and it’s full of interesting features. For the installation you have to carefully follow the instruction contained on the specific pendrivelinux pages (more instruction also available for installation using Linux). Please don’t be worried after the first reading because all the necessary steps are well explained and if you follow them it’s really not possible to make mistakes! Enjoy it!
BUM (Boot-UP Manager): the boot configuration utility for Ubuntu
Today, in our Linux page we post a review about BUM a powerful, graphic Boot-up Manager for Ubuntu. Using this light software you can modify and decide what programs run at startup. BUM is a very useful tool, precious especially when you notice that your Ubuntu boot is becoming slower than in the past. Initializing the Boot-up Manager is very simple and fast: recommended for the Linux beginners (like us)!
How to solve upgrade problems in Ubuntu: some brief notes.
Yesterday a new version of Ubuntu (Feisty Fawn 7.04) has been released. This new version seems to be more powerful and enjoyable than the 6.10 and we hope it will actively contribute to spread the use of Linux. For people using Ubuntu 6.10, Ubuntu released simple and brief instructions to upgrade fast the OS.
In our Linux Page, we posted a brief tutorial about solving problems generated by an Ubuntu upgrade (this kind of problems is not common but unfortunately sometimes it happens..). The post, inspired some Italian blogs we found on the web, is very simple and effective and we hope it could be useful… in case of emergency. See you soon!
Ubuntu Migration Assistant (UMA) in the new Ubuntu 7.04 Feisty Fawn (Beta)
The new 7.04 beta version of Ubuntu was recently released. In few weeks (or less) we will enjoy the new final version which seems to have some new interesting features. The Ubuntu Feisty Fawn version has a new codec wizard to install codecs, a powerful plug and play network sharing function which will be very useful for the evolute home networks where multimedia files are shared in shared external hard disks. In our Linux Page we posted a brief note about the new UbuntuUMA) Migration Assistant (which allows you to import Internet Explorer bookmarks, Firefox favourites, desktop wallpaper, AOL IM contacts, and Yahoo IM contacts directly from your installed Windows OS. I am sure that, in the near future, UMA will be one of the most interesting Ubuntu features for people who want to run a dual-boot system.
