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Linux Ubuntu

VirtualBox (4.26) USB Issue: “unable to enumerate USB device on port n”

After a couple of hours trying to get a USB device (USB-to-Serial FTDI) working in VirtualBox with OSX host and Ubuntu 12.10 guest and receiving an error message similar to the follow:

usb 6-3: new full speed USB device number 24 using ohci_hcd
usb 6-3: device not accepting address 24, error -110
hub 6-0:1.0: unable to enumerate USB device on port 2

It turns out, the issue lies with VirtualBox, when the machine is given more than 1 processor it fails to properly mount any USB device. The only fix I have found to work is to simply reduce the number of processors back to 1. Once it’s returned the USB devices work simply by mounting them the usual way, from the VirtualBox menu > Devices > USB Devices >.

If anyone find a better solution, be sure to comment below.

Categories
Command Line Fedora Linux Posts Ubuntu

Linux USB Errors with usb-creator-gtk “stdin: I/O error stdin: error 0 /init: line 1: can’t open /dev/sr0: No medium found”

After installing Ubuntu on a USB stick with the Ubuntu USB Startup Disk Creator (usb-creator-gtk) you might encounter an error such as the following:

stdin: I/O error
stdin: error 0
/init: line 1: can't open /dev/sr0: No medium found

This is actually a bug with the software and isn’t anything you’ve done wrong. It seems to be a bug that’s effecting users running Karmic, Lucid, Maverick and Natty so it’s a pretty wide spread issue.

The best way I have found to get around this issue is to install and run unetbootin to create live USBs. If you’re using linux it should be found in the usual place you can install things.

Installation:

Ubuntu/LinuxMint/Debian:

sudo apt-get install unetbootin

Fedora/OpenSuse:

sudo yum install unetbootin
Create a live USB:

To install a distro it’s pretty simple, either select it from the “Distribution” option and pick a distribution and version, UNetbootin will then actually download it and install it for you. Alternatively you can pick an Diskimage and browse for the ISO file you download (and would usually burn to a CD/DVD) and install from that. Select the USB Drive at the bottom and hit ok and it’ll install a bootloader, the system and you’ll be up and running in no time.

Persistence File:

If you wanted a persistence install which allows you to save files, settings and installed programs you’ll have to do a little manual work as it currently doesn’t support that option.

Go to http://unetbootin.sourceforge.net/diskimg/ and download one of the files (128mb.zip, 256mb.zip, or 512mb.zip) corresponding to the amount of persistent space you want (make sure the size of the persistent disk image is smaller than the free space you have on your USB drive).

You’ll then need to edit the syslinux.cfg file that was created by UNetbootin in the root of the directory (just open it with a text editor) you should see something similar to the following:

label unetbootindefault
menu label Default
kernel /ubnkern
append initrd=/ubninit file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash —

So on the line that starts “appen initrd=” you’ll want to add the option of “persistent”, it should then look like the following:

NOTE: WordPress changes my double dash at the end of the last line to a single long dash, this won’t work. It’s easiest just to add the final word before the double dash in the file, do not copy and paste this in to your file. If you do, you will get more errors.

label unetbootindefault
menu label Default
kernel /ubnkern
append initrd=/ubninit file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash persistent —

I added this line to all that used the “file=/cdrom/preseed/ubuntu.seed” option, since that’s the image that’s being opened and it should then change all options on the bootloader that will load the ubuntu install.

Categories
HowTo Posts Ubuntu

How To Fix “Fatal server error: no screens found” | Ubuntu

If you’re running off a live USB disk or changing your graphics card the error below might appear when Xorg is looking for the wrong drivers or device. You might also get this error while using the Nvidia drivers, I found however this was caused by some of the extra options added into the xorg.conf file (usually located /etc/X11/xorg.conf). If the case is that it’s a problem with the aditional options I suggest making a backup of the file and attempting to comment out (#) aditional options, this will need a bit more of an expert eye to see what isn’t needed though.. You can also use the following to rollback to a working version when using the Nvidia drivers.

There is a pretty simple fix, if it is caused by broken or changed xorg.conf file:

Fix:
Make a backup of your current Xorg.conf, just in case something goes even more wrong and it can be easily restored:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.bckup 

Now you’ll want to restore the failsafe (sometimes called xorg.conf.backup) config to be used as the default:

sudo cp /etc/X11/xorg.conf.failsafe /etc/X11/xorg.conf

Yeah, it was that simple (if this error was caused by a broken or changed xorg.conf anyway. So you can continue and start the x server with:

startx

Error:

X.Org X Server 1.9.0
Release Date: 2010-08-20
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-27-server i686 Ubuntu
Current Operating System: Linux ubuntu 2.6.35-22-generic #33-Ubuntu SMP Sun Sep 19 20:34:50 UTC 2010 i686
Kernel command line: noprompt cdrom-detect/try-usb=true persistent file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
Build Date: 16 September 2010  05:39:22PM
xorg-server 2:1.9.0-0ubuntu7 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.18.4
 	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Fri Mar  4 11:35:54 2011
(==) Using config file: "/etc/X11/xorg.conf"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) No devices detected.

Fatal server error:
no screens found

Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
Please also check the log file at "/var/log/Xorg.0.log" for additional information.

 ddxSigGiveUp: Closing log
giving up.
xinit: No such file or directory (errno 2): unable to connect to X server
xinit: No such process (errno 3): Server error. 
Categories
Command Line HowTo Linux Posts Ubuntu

HowTo: Mount USB Persistent casper-rw File in Linux

So, you’ve created an awesome Live USB Linux stick with a persistence file which let’s you boot anywhere and carry all your sweet sweet datas around on it too. If you want to see those files in Linux on your desktop or laptop outside the USB you’re going to have to mount the loop device (the casper-rw file) somewhere first. The following commands show how to make a folder and mount the loop and then unmount it too.

Just change the /media/USB/ for the mounted location of your mounted USB stick which contains the casper-rw file you want to view the contents of and the /home/alex/caspermnt/ for the mount point on your system.

Mount:

 mkdir ~/caspermnt
sudo mount -o loop /media/USB/casper-rw /home/alex/caspermnt/

Unmount:

 sudo umount ~/caspermnt/

This can be useful for recovering data from a borked Live USB stick or for backing up your files on your computer just to be sure.

Categories
HowTo Linux Posts Ubuntu

How To: Fix “Unknown keyword in configuration file.” Ubuntu USB Boot

Attempting Boot From USB Device

SYSLINUX 3.63 Debian-2008-07-15 EBIOS Copyright (C) 1994-2008 H. Peter Anvin
Unknown keyword in configuration file.
boot:
_

After creating a USB bootable version of Ubuntu from the Startup Disk Creator (or usb-creator-gtk) and attempting to boot, I was greeted by the error above. It might look a bit scary but it’s really easy to fix, just plug the USB flash drive into a computer (windows or linux, mac too probably but I haven’t tried that.)

Solution 1:
  1. Open the the syslinux folder in the root of the flash drive.
  2. Inside is a file called syslinux.cfg you’ll want to edit that.
  3. Find the line “ui gfxboot bootlogo” and simply remove the “ui “.
  4. Save and try booting again.

Below is how my syslinux.cfg file looks after editing:

# D-I config version 2.0
include menu.cfg
default vesamenu.c32
prompt 0
timeout 50
gfxboot bootlogo


Solution 2

Alternatively it looks as though there is another way of fixing this issue if there is no “ui” in the file, this is to do as followed (as pointed out in the comments below):

  1. Type “help” and press enter
  2. Hit Enter again

This should boot correctly and shouldn’t need to be done every time.