Diskless Gnome 3 - a short history

[jggimi]

1. A new $DAYJOB laptop

Last week, I received a replacement office laptop from my customer where I'm on a long term consulting engagement. It's a very nice laptop: light weight, very thin, with an SSD drive and nice resolution screen. Most important (to me) is its relatively speedy pair of 64-bit CPUs which I would like to use evenings and weekends for my personal projects. I've done this before -- I connect an external USB drive and use the platform or perhaps just its processors as a compute tool.

As I would normally do, one evening last week I plugged in an external USB drive and an Ethernet cable, and installed onto the drive via pxeboot(8).

My first boot after installation failed. The bootloader would load from USB and run, but any attempt to have it load a kernel from the USB drive would result in an immediate reboot. If there was an error message, I couldn't see it. The same symptom occured whether using the standard second stage bootloader boot(8) or pxeboot, if the kernel was stored on the USB drive. It would also reboot if I attempted to use the bootloader's ls command.

The laptop runs OpenBSD. And it communicates fine with USB mass storage devices when running. Only the bootloaders can't read from USB devices.

This is $DAYJOB's resource and they control it. I don't have access to BIOS controls so I cannot even inspect its configuration settings. I don't want to touch their SSD drive, so installing onto the internal drive was not an option. There's an mSATA port, but I don't have an external SATA drive available.

2. Diskless(8) thin client

I copied the installation onto one of my owned machines -- a little netbook -- and configured it to serve NFS per FAQ 6.7. Following the guidance in the diskless(8) man page, I also configured it as a rarpd(8) and rpc.bootparamd(8) server.

I now had a working, diskless OpenBSD workstation running. The details are in diskless(8), but in brief, upon network boot:

• The BIOS boots using PXE (DHCP and TFTP) to load pxeboot(8) from one of my Alix routers. Either of them can reply to DHCP requests, so I use the DHCP "next-server" option to point to the one that runs tftpd(8) -- see dhcp-options(5).
  
• pxeboot(8) loads the GENERIC.MP kernel from a router using TFTP
  
• pxeboot(8) and the kernel both obtain configuration information needed to mount the root and swap partitions using RARP and BOOTPARAMS.
  
• The kernel mounts the root and swap partitions during multiuser boot.

I found that while DHCP is used for PXE booting, that dhclient(8) shouldn't be used as the address is pre-assigned and already in use by the kernel by the time dhclient is started. Setting the static IP address in the hostname.if(5) file is better.

3. Gnome 3 - easy to install and configure


Now that I had a working laptop, my goal was to try out Gnome 3 on a platform powerful enough to run it. My little netbook isn't -- though its more than powerful enough to be the storage server for the laptop.


It really was this easy, as shown earlier this year in Antoine Jacoutot's article in the OpenBSD Journal.

# pkg_add gnome
# echo 'multicast_host=YES' >>/etc/rc.conf.local
# echo 'pkg_scripts="${pkg_scripts} dbus_daemon avahi_daemon gdm"' >>/etc/rc.conf.local

To this I added a number of browsers, Libreoffice, hplip-gui, and a few other packages, including Antione's lovely toad package for automounting filesystems on Gnome. I also added Gnome's Cantarell font to my xorg font list, though that's not strictly necessary.

I wanted to disable the bothersome internal trackpad, so I created two xorg.conf(5) Sections: A ws(4) InputDevice addressing an external mouse via /dev/wsmouse1, and a ServerFlags setting to turn off the AutoAddDevice option. This effectively disabled the trackpad at /dev/wsmouse0 and let me use my own USB-attached mouse.

Gnome is a huge investment by quantity of installed packages and the resultant capacity requirements for /usr/local -- lots of GB. But I'm finding it easy and intuitive. And I say this having been a cwm(1) user for several years, and a fluxbox user before that.

Antoine's article has a link to this 2.5 minute video of Gnome 3 on OpenBSD.


I'm very impressed with it. I wish my netbook was fast enough to use it.