Linux

Ubuntu (all variants): wireless USB keyboard unresponsive with LUKS full-disk encryption

Hardware, Hints and Tips, Linux, Open Source, Operating Systems, Software , , , , , 0 Comments

If you’ve been following my posts lately, you’ll have seen that I’m quite keen on encryption and privacy, particularly following the ongoing Snowden revelations, and the 2013 GCSB furore here in New Zealand.

So I went out and purchased my favourite flavour of super-robust USB drive, the beautiful Corsair Survivor 3.0, and proceeded to install Linux Mint on it with LUKS full-disk encryption.  You can see an overview of how I did this at my blog post here:  http://www.gravitycomputing.co.nz/installing-linux-mint-usb-drive/

But there was a problem.  When the system prompted me for the password to unlock my newly-encrypted drive, the password prompt wouldn’t take any input.  In fact, the keyboard was completely unresponsive, even though it worked fine in the BIOS!

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Restoring from a RAID drive failure in Ubuntu

Restoring from a RAID drive failure in Ubuntu

Hardware, Linux, RAID, Repair, Software , , , , , 0 Comments

One inevitable outcome when working with multiple RAID arrays is that you are going to encounter drive failure at some point, no matter how well you prepare. Luckily, when it comes to Ubuntu, the process to replace a failed drive is not terribly difficult.  You’ve probably arrived here because you already have a RAID array with a failed drive in it, and you’re looking for a tutorial to replace it.  So this tutorial is written for people running Ubuntu, already with an mdadm RAID-1 array set up and running.

Replacing a failed drive in a RAID array is fairly straightforward, provided they're not engulfed in flames.

One possible cause of hard drive failure

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Installing Linux Mint to a USB drive (Portable OS)

Installing Linux Mint to a USB drive (Portable OS)

Linux, Software , , , 0 Comments

One of the most handy tools to have in IT support is a portable OS. Whether you want to perform a memtest, repair a faulty bootloader, scan for a virus or rootkit, or extract some mistakenly-deleted files from another drive, having a bootable USB drive around makes doing such things quick and easy. So in keeping with that idea, I present to you a step-by-step guide of how to install Linux Mint on a USB drive.

This also works for Ubuntu, Xubuntu, Lubuntu, Ubuntu GNOME, etc.

  • First of all you’ll need two USB Sticks – your intended boot stick should be at least 8GB in size; the intended installation stick will be fine with 2GB.  I highly recommend using a USB 3.0 drive for your boot stick, to take advantage of the extra speed.
  • Download your Linux distro. I’ve gone with Mint 15 (because it’s pretty), and chosen 32 bit for compatibility with other PCs.
  • Insert your intended installation stick and put your chosen Linux on to it:
    • In Linux, use something like:  sudo dd if=~/Downloads/linuxmint-15-cinnamon-dvd-32bit.iso of=/dev/sdx
    • Under Windows, use UNetbootin to image your installer to the USB stick.
  • Once your installation stick is ready, plug in your boot stick.
  • Boot your computer onto the installation stick, and select “Install Linux Mint”.
  • Follow your nose until you reach the Installation Type screen.  At this point, choose ‘Something else’ and click continue:

PortableMint01

Warning:  be VERY certain of your target. Linux identifies different devices by letter (sda, sdb, sdc) and different partitions by number (sda1, sdd1, sdc2).  As you can see below, mine is /dev/sdb.

  • Wipe the partition table on your boot stick if required; it should appear as a device containing only free space:

PortableMint03

  • Select ‘Free Space’ on your boot stick, and add a partition with the following characteristics:
    • Size: 512mb or over
    • Type: Primary
    • Location: I chose beginning; this is up to you
    • Use as:  Up to you; I went with Ext4
    • Mount point: /boot

PortableMint04

  • Once your boot partition has been created, it’s time to create your encrypted file system.  Select ‘Free Space’ on the boot stick again, and create a new partition like so:

PortableMint05

  • After I took the above screenshot, I decided I wanted an unencrypted space on the drive to allow me to share the drive between Linux and Windows.  To achieve this, I actually only used 20GB for this partition.  This allowed me to add a FAT32 partition later.  You can do this too, if you want.
  • Clicking OK will create the new encrypted partition, mount it, and then create an Ext4 partition inside it as /dev/mapper/sdx_crypt. Select this new partition for your installation:

PortableMint06

  • Make sure that you select the correct device for the boot loader installation!  You want to choose your boot stick.  Do NOT choose /dev/mapper, use /dev/sdx instead.

PortableMint07

  • Edit your /dev/mapper/sdx_crypt partition and set a mount point of /.

PortableMint08

  • Click “Install now”. The installer will alert you that you haven’t provided any swap space.  This is fine – click continue.
  • Follow your nose through the rest of the installation.

Once the installation is completed, you may want to set up a a swap file if you’re planning to boot on a system with low memory.

Microsoft Office under Linux: .lnk files, WINE, Crossover, and you.

Microsoft Office under Linux: .lnk files, WINE, Crossover, and you.

Linux, Office, Software , , , , , , 0 Comments

For the past three years or so, I’ve been running Linux exclusively on all my desktop PC’s. I used Ubuntu until they moved to the new Unity interface (which I hated), then tried Lubuntu for a while, went through Xubuntu and Kubuntu, and then settled on Linux Mint last year.

However through all of this, I’ve never been able to rely on LibreOffice or OpenOffice for my documents. It’s just not mature enough to go head-to-head with Microsoft Office. [I just learned that LibreOffice 4.0 has been released – I’ll give it a try and see how it’s coming!]Office 2010 works great under WINE, except for the dozens of lnk files

The solution, for me, is to run Microsoft Office under an environment such as WINE, PlayOnLinux, or Codeweavers Crossover (all of which are actually WINE, of course). Office 2010 works great under WINE, apart from the dozens of unwanted lnk files.

I’ve been running under Crossover since about 2010, after I got a free version from Codeweavers’ Lame Duck Presidential Challenge, which has probably been one of the greatest marketing moments in history.

Now that I’ve given you the history, here’s the reason for this post:

Office 2010, under recent versions of both Crossover and WINE, has this awful tendency to scatter-spray dozens of .lnk files all over my file system. This is made marginally worse by the fact that the operating system doesn’t recognise them as Something That Should Open In Word(tm).

Turns out this is a bug in WINE. The resolution is to create a “Recent” folder, like so:

mkdir ~/.cxoffice/Microsoft Office 2010/drive_c/users/crossover/Recent

To be a bit more abstract, that is:

~/.cxoffice/<Office bottle name>/drive_c/users/<crossover username>/Recent

If you’re using PlayOnLinux or WINE, you won’t have a .cxoffice folder – you’ll need to do this under the .wine folder instead. Simply replace .cxoffice in the command above with .wine and you’ll be good to go. The Recent folder should now contain any .lnk files created by Office.

I found this solution on the Crossover Support Forums at this link: http://www.codeweavers.com/support/forums/general/?t=26;msg=128936

Running ‘sudo reboot’ causes shutdown with Intel C224 chipset

Running ‘sudo reboot’ causes shutdown with Intel C224 chipset

Hardware, Linux, Operating Systems, Server , , , , , , , , 0 Comments

The Intel C224 chipset requires some tweaking in order for Ubuntu Server to reboot

The Intel C224 chipset requires some tweaking in order for Ubuntu Server to reboot

When setting up a server recently (the one mentioned in this post), I encountered an odd problem: running sudo reboot would power down the machine, instead of rebooting it! This was occurring on a new Supermicro X10SLM-F motherboard with an Intel C224 chipset, running Ubuntu Server 13.04 Raring Ringtail.

It turns out that the problem is caused by buggy Intel drivers, and the problem can be resolved by blacklisting the mei driver. In order to do this, open up a terminal and enter the following:

$ sudo nano /etc/modprobe.d/blacklist.conf

Then add these lines:

# Don't load MEI driver; this allows system to reboot
blacklist mei

Save and exit the file, and enter the following into the terminal:

$ sudo reboot

The machine should now reboot without any problems

Credit goes to Ubuntu forums user thomasberger for offering the solution: http://ubuntuforums.org/showthread.php?t=2024096

No display on boot in Ubuntu Server 13.04

No display on boot in Ubuntu Server 13.04

Hardware, Linux, Operating Systems, Server, Software , , , , , , , , , 0 Comments

When performing a recent server setup, I encountered an annoying display problem. The install completed without any problems, but there was no video on boot at all – sometimes the Grub menu appeared (but usually not), and after that the monitor went to sleep. SSH access was working fine, proving that it was only a display issue and not a boot fail.A boot issue gives rise to an annoying display problem

The setup involved installing Ubuntu Server 13.04 (Raring Ringtail) onto the server, which contained a new Supermicro X10SLM-F motherboard with an Intel C224 chipset.

After doing some research I found that the solution was to enable nomodeset in Grub. Because I had set up OpenSSH during Ubuntu install, I was able to connect to the server and do the following:

$ sudo nano /etc/default/grub

 

Find the line 

GRUB_CMDLINE_LINUX_DEFAULT=""

 

Change it to 

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"

 

And then enter the following commands into the terminal 

$ sudo update-grub
$ sudo reboot

 

When the server rebooted, everything loaded as normal.

Sharing Remmina folder and backups with SpiderOak for Ubuntu

Sharing Remmina folder and backups with SpiderOak for Ubuntu

Internet, Linux, Security, Software , , , , , , , , 0 Comments

Given that Gravity Computing is such a widely-located company, working with sensitive data, it’s important that we have a platform in place that allows us to share resources between each other while keeping them secure. We’ve been using SpiderOak – a cloud-based service similar to Dropbox – which is strongly focused on privacy and security. Symbolic link symbol

One of those resources we share is the remote connection details for some of our clients. In Ubuntu we use a popular remote connection client named Remmina, which is well regarded for its ease of use and stability. We could each enter the remote connection details into Remmina ourselves, but that would take up unnecessary time and create a time lag if one person is waiting on details from someone else.

A better way of doing it? Create a symbolic link. Remmina stores its remote connection data in a hidden folder in the user’s home directory (i.e. /home/user/.remmina). If we were to store a master copy of the .remmina folder in SpiderOak and then have each desktop link to it, the remote connection details could instantly be accessed and updated from any location.

Even if you’re not all that familiar with the terminal, the process is really very simple. The series of steps below will create a symbolic link between the master .remmina folder and the SpiderOak hive folder. It will delete any Remmina connections that you’ve already saved, so we take a backup of them first.

$ mkdir ~/remminaBackup # Create a folder to contain your old Remmina files
$ mv ~/.remmina/* ~/remminaBackup # Move your old Remmina files into your backup folder
$ sudo rm -rf ~/.remmina # Remove the existing Remmina directory
$ sudo ln -s '~/SpiderOak Hive/Remmina/' ~/.remmina # Create the Symlink
$ cp ~/remminaBackup/* ~/.remmina # Copy your old Remmina files into your new Remmina folder

You can delete your remminaBackup folder once you’ve tested your old connections to make sure they still work.

Note that the command is entered in the format “sudo ln -s MASTERLOCATION LINKLOCATION”. Note also that the master location is encased in apostrophes, due to the fact that ‘SpiderOak Hive’ contains a space and would otherwise throw off the command.

Finally, you need to test the Symlink to make sure that it works correctly. The easiest way to do this is to navigate to the .remmina folder in a terminal and check that it contains the required files:

$ cd ~/.remmina # Enter the .remmina directory
$ ls # Check the contents of the .remmina folder

You should be greeted with a folder that contains .remmina files, and is identical to your master Remmina folder. If this is not the case, make sure that you have entered in both locations correctly, and that any file path longer than the current folder begins with a backslash.

And voila! You now have a secure repository allowing all your PCs and Servers to be shared within your team.

Getting the Brother HL-2040 to print under Ubuntu 11.04 “Natty Narwhal”

Getting the Brother HL-2040 to print under Ubuntu 11.04 “Natty Narwhal”

Hardware, Hints and Tips, Linux , , , , , 4 Comments

Our Brother HL-2040 printer is a great little workhorse, and has always worked pleasingly well under both Windows and Linux (and as a shared printer). However when I upgraded from Ubuntu 10.10 to 11.04, it went a little bit haywire. No matter what I did, the printer’s response was to print infinite blank pages. Fortunately, the fix is easy! More →

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