An Edubuntu Installation for St. John’s

This was really way too easy…

The school computer lab (and also the rest of the student computers in the classrooms, and to a lesser extent our faculty machines) is being impacted by the end of life for Windows XP. Most of the machines are XP Pro, some XP Home. There are a couple of W7 machines as well. The machines are all pretty old (most are 2004 vintage), and are increasingly having issues of one kind or the other. I installed W7 on one of them, and it craaaaaaawwwwled, even after I dumped an extra couple GB of memory in it. I’ve been spending an increasing amount of time keeping the things updated, and even with the remote access tools I have been deploying the past couple years, I’d still have to go around to 30 or 40 machines for some things.

The machines also got “lab rash” from kids playing with settings they were able to, and would occasionally jack a machine up by inverting the display or whatever, so I would end up going by to fix it. And that’s even with Raegan being very swift on fixing stuff.

So I started looking at alternatives, and decided that Edubuntu was the best candidate. It had all of the existing software that we currently use, and a lot more. It has thin-client capability, so that would end kids jacking with the machines.

Edubuntu needs a fairly beefy server. I had a donated machine from an oil company that sported a 3.8 GHz Xeon and no less than four 146GB SCSIs moving along at 320MB/s (with space in there for a second processor if I can find one cheap). It has dual power supplies and enough fans to build a drone, and *two* GB Ethernets. It is, BTW, also fairly old, having been introduced in 2004. That explains why it has two USBs, *and* PS/2 connectors. The machine came with the six memory slots filled with 1GB DDR2 ECC memory sticks. I happily filled the six slots with 2GB DDR-2 memory, and the poor machine squawked at me until I turned it off. Turns out it ONLY wants ECC memory, and the memory I had was non-ECC. Oh well.

For 20 machines, Edubuntu recommended 20GB of disk (not a problem there) and 4GB of memory for every 20 clients. So 6GB is comfortable (especially since I am planning on running the browsers locally). I will probably haunt eBay and get at least a couple more sticks of ECC memory also.

I drew up a couple iterations of how I would deploy the thing on the school network, decided it would work, and started the process. I have a couple weeks until school starts. I knew the good news was, since I was deploying thin client network-boot clients, that I wouldn’t have to change the lab workstations at all, except to enable net booting, and so I could fall back to the XP workstations at any time.

So I download the latest Edubuntu, popped the DVD into the machine, and started the installation process. All was smooth until I got to the part where you identify the disk to install Edubuntu on.

Now, when the server was donated, I had wiped it for the company that donated it, and then dropped Fedora 16 on to it to play with. That all worked fine.

So when Edubuntu got to the Installation Type page, it asked if I wanted to use /dev/sda, and that there was Fedora on it, and if I used the whole disk then the Fedora would be wiped. That didn’t bother me, so I selected it, and the Use LVM option, and told it to Continue. I got the Erase Disk and Install Edubuntu page, verified that /dev/sda would be used, and clicked Install Now. The Install button greyed out (only one shade of grey), the page title changed to Installation Type after about 10 seconds, and the Install Now came active again. Hmmm… Clicking Install Now again takes you back to the actual Installation Type page (with use entire disk and use LVM). This cycle repeated (eight times I tried it).

So off I went to research. The existing Fedora would still boot. I installed Edubuntu on another computer to show the media was OK. I posted a query to the Ubuntu Forums. I kept coming back to the existing Fedora installation. I’ve done a lot of installs of a lot of OSs, and most of them would happily overwrite an existing OS, so I was skeptical that was the problem. In fact, Edubuntu happily overwrote a Linux installation that was on the workstation I used to show the media was OK. But the existing Fedora on the server was LVM, which is a technology not fully supported by some Linux tools (like gparted). I hadn’t any suggestions from the Ubuntu Forum (which surprised me).

So I decided to zorch the Fedora LVM installation. It wasn’t entirely straightforward; LVM is not as well documented as it could be, there is a wealth of similar-looking beta, with some slightly contradictory. Here is what I ended up doing:

  • I booted the server using a Fedora Live CD (it was the Security Spin for Fedora 15).
  • Used lvdiskscan to identify the LVM. It had four PVs, and three what I would have called mount points: root, home, and swap.
  • Used lvremove for the root and home partitions. When I tried to remove swap, it complained that swap was active (!). This is probably what confused the Edubuntu installer. I used swap off -v to turn off the swap mount point, then was able to use lvremove to remove it.
  • Used vgremove to take out the volume group.
  • Used pvremove for the four PVs.

I rebooted the machine and replaced the Fedora CD with the Edubuntu DVD. Installed without a hitch.

The key to the LVM removal was to take out the mount points first.

So clearly there is a buglet in the Edubuntu installer that does not like existing LVMs, or perhaps does not like swap partitions in particular.

Once the server rebooted, I connected a switch to the LTSP port, and then a Dell workstation to the switch, started it, and switched it to network boot in the BIOS. It still booted from the disk. I restarted it, went back into BIOS to disable the disk, and on reboot it came up over the network, and I had my thin client running.

One more glitch: the Fedora I installed to play with automagically added all four disks (PVs) to the LV with no prompting from me, so instead of installing to a 146GB disk, I had a 550GB+ logical disk. The Edubuntu install put LVM on, but only with the single disk. I will manually add those using pvcreate and then lvextend this evening or tomorrow, but it is one more thing to do.

I’ve a long list of stuff to do. I need to add a student user, add some software, enable local access to USBs, add access to our St. John’s shared disk, and get the remote management tools working. I will get a graduate level course in rebuilding the client image as this goes along.

I’m also interested in hauling the server to school and plugging it into the lab network, and watching all those machines boot up simultaneously.

But the really amazing this is how slick it was with the Edubuntu DVD. There is a heck of a lot of capability there.

06 August 2014, 2200 Update:

I added two of the three other disks to the LVM installation, using a set of excellent instructions at http://www.rootusers.com/how-to-increase-the-size-of-a-linux-lvm-by-adding-a-new-disk/. So now I have a 410GB space to play in. I didn’t put the fourth disk in as the SMART disk function was reporting a future failure.

17 August 2014, 1239 Update:

I’m building a second server for the school to host a student management system, a local storage cloud, and WordPress for the teachers.  It’s also Ubuntu based, also 14.04, and had a disk in it with a Fedora 10 LVM instantiation.  This installation went right over the Fedora 10 with no comment. 

BTW, Unity on this one is sloooooooow.  I installed FXCE, which I am used to from a number of Live CDs I use, and it runs darn fast.

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