This series of labs consist mainly of an adaptation of a one-off lab that was presented at Fall IDF in San Francisco, but now there are three very large trucks driving all over the US teaching a lot of people. This means that systems need to be “restored” to new after every lab, to prepare for the next city.
Problems we have encountered (and solutions too).
These problems will occur for users who try these labs on their own, if they try a series of the demo installations for the Intel Embedded Development Board N-450. The problems occur because of the assumptions of the OS installation scripts, or because there are bugs in the install procedures. Once you get round these install “features” all of the OS’s work well, but it can be very frustrating to get stuck at step one or two.
Problem A: Brand New Disk. This was found at IDF when we tried installing an OS on a factory fresh SSD. Obviously this only happens once per disk, so it took a while to determine what the hangup here is. It has to do with a new disk not having a disk label. See Solution Number 1 below
Problem B: Fedora and LVM. The Fedora install for the E6XX uses the Logical Volume Management features, but that causes problems when trying to re-install Fedora, or to install another OS, say Meego, when trying to remove and re-partition a disk that uses LVM.
Problem C: Disk with no Partitions. This is really an outcome of problem B above, and we caused this problem by using a manual method to remove the LVM info, but didn’t write a new blank partition. Android-X86 install chokes on this, for example, but doesn’t actually display and error, it just ignores the disk.
Solutions. As I implied above the bad news is that these problems are within the installation scripts of these particular OS examples that we are using for the labs. The good news is that these same OS installation images can be used to manually fix the problems, and allow for subsequent installations either of the same OS, or a different one.
Solution #1: Create a Meego Installation USB disk, and start up your target system and select Boot Meego from the first screen. Once it starts, select another login console using CTRL-ALT-F1, and login as user “root” with password “meego”. Then run fdisk to remove any partitions and add a new blank one, see FDISK section below for and example.
Solution #2. Use the existing installation. One of the recommendations at the lab was to use “intel2010” as the password for all users, and installs requiring a password. This allows the lab staff to login as root on a console, and use the same FDISK commands for solution 1 to wipe out the disk contents. This process also works for Ubuntu, but unfortunately not for Android-X86.
Using FDISK to prepare a system for (re)-installation.
This automagically works for Problem A, in that fdisk will create and assign an MS-DOS label to the disk. You do need to Write to the disk to make this work however.
When I invoke fdisk, this time for /dev/sda, I always like to check I have selected the correct disk by typing P for Print to make sure I’m not about to format my USB stick, but it also shows how many partitions have to be deleted. The screen above shows a Linux LVM System for partition 2 (/dev/sda2), as this is from a Fedora install on an E6XX system.
To correctly initialize this system we would need two Delete commands, a New partition command, and final Write command to apply these desired settings. If you see three, or more, partitions, just keep pressing D, until they are all gone before adding a New partition.
The screen above shows an error message because I was using solution #2, and it makes sense to get an error, as I’ve just used a program to delete the entire disk that the fdisk program resides on. You won’t get this error if you use Solution #1, as the OS is stored on a separate USB disk, and not the /dev/sda SATA disk.