seife’s assorted rants

Since a few(?) releases, you can simply “dd” your openSUSE ISO-file onto an USB stick and boot from that, which is pretty cool and which I use a lot.
But recently, I came across a machine that simply does not boot from the USB stick. No matter what settings I tried in the BIOS - no boot. I believe it will only boot from internal hdd, internal CDROM or internal floppy and via PXE.
Instead of just burning the ISO onto a CD and using that (that would have been too easy, wouldn’t it?), i booted an old rescue system I had still lying around on CD and found out, that the BIOS actually does enumerate the USB stick on boot, at least it shows up in /sys/firmware/edd and /dev/disk/by-id/edd-int13_dev81, so I wondered how to boot from it.

The answer was easy: Just copy what the openSUSE CD does for “boot from local harddrive”. It’s actually very easy (/tmp/x is the root directory for the ISO)

mkdir -p /tmp/x/isolinux
cp /usr/share/syslinux/isolinux.bin /tmp/x/isolinux/

Then create a /tmp/x/isolinux/isolinux.cfg file, with the following content:

say ***********************************************
say seife's USB boot enabler
say enter 0,1,2,3 for disk 0-3
say disk 0 is usually your local built-in harddrive
say disk 1 is probably your USB stick
say ***********************************************
label 0
        localboot 0x80
label 1
        localboot 0x81
label 2
        localboot 0x82
label 3
        localboot 0x83
default 0
prompt   1
timeout  0

That’s it!
Create an ISO from it with:

genisoimage -o /tmp/sys.iso \
    -b isolinux/isolinux.bin -c isolinux/boot.cat \
    -no-emul-boot -boot-load-size 4 \
    -boot-info-table \
    /tmp/x

And burn onto a CD. Voila, your USB boot enabler is ready!

Now I only need to find a small credit-card size CD-R blank somewhere

And maybe Steffen Winterfeldt puts something like that as a hidden option into the default openSUSE ISOs. It would be quite useful IMHO.

This https://bugzilla.novell.com/show_bug.cgi?id=429772#c22 is the “official” documentation. It’s the same what Marius already wrote in his comment on my last post on the topic, but I’ll mention it here again, so that it gets found more easily.

In openSUSE 11.1, NetworkManager is supposed to handle all dialup stuff. But, as far as I know, it can not handle e.g. plain old phone modems or dialup via bluetooth (rfcomm).
Unfortunately, if you now try to use the old methods of kinternet, wvdial or Umtsmon, you will find out that dialup will work with these, but you won’t get a working resolv.conv and thus no name resolution. The reason is that the netconfig tools, which do rewrite resolv.conf apparently refuse to do that if NETWORKMANAGER=yes is configured in /etc/sysconfig/network/config.
One solution would be to switch to the old ifup method (NETWORKMANAGER=no), but then wireless LAN will basically be unusable.
Another, dirty and hackish solution is this:

Create a /etc/ppp/ip-up.local, containing

        #!/bin/sh
        echo "nameserver $DNS1
        nameserver $DNS2" >> /etc/resolv.conf

and a /etc/ppp/ip-down.local, containing

        #!/bin/sh
        mv /etc/resolv.conf.netconfig /etc/resolv.conf

Make both of them executable. Dial up.

How does it work? The ip-up script gets the DNS servers in its environment. Just before it exits, it calls the ip-up.local script which then appends them to resolv.conf. During ip-down, the netconfig tools notice that the resolv.conf was changed externally and they refuse to touch it. They instead create resolv.conf.netconfig. ip-down.local now just replaces resolv.conv with resolv.conf.netconfig and everybody should be fine again.

To make this hack a bit more robust, you should probably check if the $DNS[12] variables are non-empty before adding them and you should check if resolv.conf.netconfig is newer than resolv.conf before restoring, but I leave that up to the reader.

Oh - and don’t forget to file a bug against NetworkManager if it cannot handle your device!

Last week, I was attending the NLUUG autumn conference, themed “Mobility” (Unfortunately, there is no usable english page, but at least the programme should be available here). I was giving two talks on the topics “suspend” and “UMTS/3G”, which went pretty well.
Apart from the 10+ hours train ride to and from Ede, this was a very nice event with many good talks and lots of interested and interesting people. Additionally, the ELC-E Embedded Linux Conference Europe was held simultaneously, which provided for even more interesting talks. Unfortunately I could not stay for the second day of ELC-E talks, because I had to take care of returning home in time for the weekend.

The papers are already up on the conference website, I assume that the slides will follow soon, too.

So they made quite some fuss about this “cool new news site”. When i finally looked at it, it was too bad for words.
I hate sites, where i have to hit CTRL-+ (for “make font bigger”) in Konqueror twice just to be able to read the main text, not to mention the fine print. Or, as a colleague put it nicely: “what i wonder, is if the people who design e.g. novell.com or news.opensuse.org never use that same browser tab to go visit google.com …” (Hi, Seth!)

And that from me, who always said he hates that web 2.0 stuff and thinks that nobody is going to read all that crap. Oh well.

So at this place you will be reading my various rants, most of them probably around Open Source Software, Linux and some tech gadgets, so generally highly uninteresting and mostly boring stuff.

Enjoy your stay.