The BFC Computing Weblog

Just a quick note for the search engines to find - peth0 can go missing from ifconfig if there is a GATEWAY= entry in ifcfg-eth0 (anaconda puts it here) and presumably -eth1, etc.. Put the default gateway in /etc/syconfig/network instead and use route-eth1 files instead to specify gateways.

Reboot for xend to do its setup correctly (please commment if there's a way to do this without reboot that works...) and instead of 'no peth0' you'll find one now exists. Also, your xenbr0 will be set up properly.

If you're seeing this, this article isn't quite done yet. Still setting things up right.

Fedora client, Nexenta Server.

On the linux side, start rpcidmapd and set it to start on boot.

service rpcidmapd start
          chkconfig --levels 345 rpcidmapd on
          

Wherever your DNS is, make sure your forward and reverse are set up correctly. No, really, make sure.

$ host my.linux.host.fqdn
          my.linux.host.fqdn has address 1.2.3.4
          $ host 1.2.3.4
          4.3.2.1.in-addr.arpa domain name pointer my.linux.host.fqdn.
          

Make sure dnsdomainname returns correctly on the linux host. You need to have my.linux.host.fqdn first on the line with 127.0.0.1 in /etc/hosts. This sets the NFSv4 domain name. Restart rpcidmapd if you needed to fix this. If this is wrong your files will all show as nobody:nobody on the mount (at this point everybody in the mailing lsit archives gives up and goes back to the crummy NFSv3). Make sure linux's dnsdomainname matches the output of Solaris's:

cat /var/run/nfs4_domain
          

Now, share under zfs:

zfs set sharenfs=rw=my.linux.host.fqdn,root=my.linux.host.fqdn pool/vol/subvol
          

mount under linux:

mount -t nfs4 solarismachine:/vol/subvol /mnt/localmount/ -o rw,intr,hard,proto=tcp,port=2049
          

Then set up a root nfs mount by:

blah, blah, blah, todo, todo, todo
          

I've got Jolicloud on the wife's netbook, and it's a nice easy-to-use distro.

Trouble is, it's based on Jaunty, which has old mythtv packages. These won't connect to our MythTV 0.23 backend in the TV room.

There is hope, though, the Avendard repo has newer packages compiled for Jaunty, but they're a bit tricky to install.

The process roughly:

Create a file:

/etc/apt/sources.list.d/avenard.list
          

with the lines:

deb http://www.avenard.org/files/ubuntu-repos jaunty release
          deb http://www.avenard.org/files/ubuntu-repos jaunty testing
          

and run the commands:

wget http://www.avenard.org/files/ubuntu-repos/ubuntu-repos.key && sudo apt-key add ubuntu-repos.key && rm ubuntu-repos.key
          apt-get update
          

to pull in the new repo. Now, remember this is dpkg/apt, so we can't just go installing mythtv first as the dependency resolution needs a bit of help.

First do:

sudo apt-get update
          sudo apt-get install nvidia-glx-185 nvidia-185-libvdpau nvidia-185-kernel-source
          sudo apt-get install libvdpau1
          

Now do:

sudo apt-get dist-upgrade mythtv-frontend mythvideo
          

and whichever other modules you need.

Then run:

sudo dpkg-reconfigure mythtv-common
          

to set your backend password.

Finally, install nfs and autofs to be able to mount your storage directory:

sudo apt-get install autofs nfs-common
          

and then edit:

/etc/auto.master
          

uncomment the /net entry, save, and run:

/etc/init.d/autofs restart
          

Then symlink to however you have your backend storage configured, e.g.:

ln -s /net/192.168.1.10/storage/ /storage
          

Now, launch mythfrontend from the Jolicloud Sound & Video group, where it will ask you for sudo access to add your user to the mythtv group and logout. Do it.

Log back in again, launch MythTV again, and go into 'Setup' and configure the storage directories for your media and/or recordings. Set parental controls as needed, they're front-end specific. Change the theme if needed, and set your painter to OpenGL if appropriate.

Those being done, you should be good to go to exit and start MythFrontend from the menu and just use it normally. SD MPEG-2 DVD video streams over 802.11g seems to work fine here in an ASUS 1000HE netbook. And now you have the world's most complex second(third,fourth) television.

Update: Jolicloud support writes via Twitter: "Adding third-party repositories could compromise your configuration. We won't be able to provide you support. ^CD" I suspect if you're reading this you can handle your own support, but be forewarned if you count on Jolicloud support. Personally, I'd rather see them engaging and supporting their community, but I understand about resource constraints.

There's a problem when running two X-displays with MythTV - some events on the non-Myth screen will steal focus and then the MythTV controls will no longer respond. This thread describes the problem well, but is now closed for comments.

Since then, mouse-switchscreen has been written, and solves the problem correctly. It's possible to bind the program to a hotkey.

In the end, I found it better to just run one display at a time since I couldn't prevent the focus stealing.

Redhat recently released a set of virtualized I/O devices for KVM, the kernel virtual machine. This short post will outline a method of converting a Windows Vista install (on KVM) to the new drivers using Virt-Manager. It has been tested on Fedora 11.

1. Make sure Vista VM is up to date on patches and the disk is error free.

2. Download drivers from Redhat network or here.

3. Mount the .iso file as a CD-ROM device.

Now you might think you can use the ‘Add Hardware Wizard’ here and add the drivers, add the hardware, and be good. I did. I wound up with an unbootable disk. Apparently Vista’s autodetection is required in this process. So…

1. Add a new network device of type ‘virtio’. Vista will do its “you’ve got hardware” routine and run you through all of its wizards. When it asks you for drivers, point it at the i386/2008 directory on the driver disc image. Yes, Yes, OK, Yes, Really, Continue, etc.

2. Shutdown the VM and remove the old ethernet controller. Boot up Vista and make sure the network works. You can conceivably skip this step for now if you want to make troubleshooting harder.

3. Add a new Storage controller. Leave the existing one as-is for now. You’ll have to pick a disk image you’re not using right now, or make a new one. Anything is fine, we’re not going to ever use it inside Vista. Do the driver dance again.

4. Shutdown Windows. Remove the storage controllers, and add a new one, type ‘virtio’, with your normal hard drive image. Take care of the old ethernet controller here too, if you ignored my previous advice.

5. Boot Windows normally. It should now be coming up on VirtIO disk and network drivers. If you get a bluescreen or a plea to use the RepairCD, something went wrong. Use the repair CD to restore to a previous restore-point and try again.

If anybody knows where to find a sound driver, please leave a comment!

For folks who are running the current development, or soon-to-be-just-released Fedora 11, you might find Firefox to be very crashy. It's not because it's the semi-controversial 3.5b4 version (which is excellent), it's because of a buggy library.

I'm running it with the Tree Style Tab and NoScript extensions, and can get a crash half the time when Session Restore is running, and almost all the time when I allow a site in NoScript.

If you run firefox from the console, so you get the debug messages, you'll see:

cairo-ft-font.c:554: _cairo_ft_unscaled_font_lock_face: Assertion `!unscaled->from_face' failed 

when the crash happens. I tracked this down through the Mozilla and Freedesktop bug systems to a problem with the Cairo graphics engine improperly disposing of fonts which it didn't own, for which a fix was incorporated last December. However, the version of Cairo shipping in Fedora 11 is older than that.

So, I applied the simple patch, fixed up the .spec, and put up some new RPM's for i386 and an SRPM for hackers and x86_64 users to build (rpmbuild --rebuild cairo-1.8.6-3.fc11.src.rpm).

I haven't tried cross-compiling from i386 to x86_64 before, and --target=x86_64 doesn't work, so if anybody can tell me how to do that short of learning mock, please leave a comment and I'll put up RPM's for that too.

The Redhat bug is here. Hopefully it gets accepted soon.

Here's a technology idea: combine a solid-state flash drive, a synchronization engine, advanced virtual memory techniques, and a portable hardware abstraction layer to create a portable computer state device.

The idea would be like this: you have a small hardware device that you bring with your anywhere. When you plug it into one of your computers, it would synchronize the filesystem states, restore memory images, and resume your computing environment the way you left it at the last location.

It's roughly equivalent to the idea of network computers, except you don't need the ubiquitous ultra-high-speed Internet that doesn't really exist (when wireless gigabit is pervasive, this would become passe).

Current reasons this can't work, using linux as the obvious OS to start with, include the lack of an abstract HAL (root drive, home drive, etc) and the lack of virtual-memory restore on a per-process basis. Lots of the other parts exist already.

Initial limitations would probably be a restriction to the same hardware architecture (x86, AMD64, ARM, etc), inability to deal with filesystem changes greater than the capacity of the SSD, and an inability to restore stateful network connections (an IP proxy might work around the last one).

One company has made an approach at this experience by running the environment directly on the portable device, but this forfeits local resources and demands power draws unachievable on an external bus (for simple connectivity). That approach may gain viability over time, though, but not yet.

Would you, gentle reader, use such a device?

KDE 4.2 looks like it's finally the right version to get me to use Linux as my daily desktop. 4.5 has more goodness baked in, 4.1 was insufficient, but 4.2 looks 'just right'. I used to be a GNOME user, but with GNOME's track towards Microsoft API's (mono) for its centerpiece applications I've gone over to KDE, and with its recent switch to LGPL I couldn't be more optimistic about its future.

For those who like to run official '-stable' versions of everything in Fedora, stop here. It'll be in Fedora 11 in a few months. Go read the warnings at the kde-redhat and the tracking bug if you want to know all the theoretical risks involved.

But for those eager to get on with things, I'll distil down what I think is the minimal command set to install the '-testing' release of KDE 4.2:

cd /etc/yum.repos.d

sudo wget http://blog.bfccomputing.com/files/kde.repo

sudo rpm -Uhv http://download1.rpmfusion.org/free/fedora/releases/10/Everything/i386/os/rpmfusion-free-release-10-1.noarch.rpm

sudo yum -y groupupdate kde-desktop

sudo yum -y update

(answering Y to importing GPG keys)

log out, log back in. You should be good to go.

I started with a working KDE 4.1 install, which wasn't easy either. If you haven't gotten that far first, be sure to do so. I have this in my notes from trial and error getting all the correct packages installed:

yum -y install kdebase kdegames kdegraphics kdemultimedia kdenetwork kdepim kdeplasma-addons kdeutils kipi-plugins PyKDE4 digikam-libs ebook-tools-libs kdebase-libs kdegames-libs kdegraphics-libs kdemultimedia-libs kdenetwork-libs kdepim-libs libgadu system-config-printer kdeaccessibility kdeartwork kdebase-workspace system-switch-displaymanager

but it may not be comprehensive (leave notes, please). Run 'system-switch-displaymanager KDM' to get the correct display manager selected. If your logins never succeed there are more packages to install. Unfortunately anaconda doesn't give a working KDE install, even if you select it at install-time.

To verify the Fedora 10 package downloads, you need the new key they're signing the Fedora 10 packages with, but it's only included in the -release rpm which you don't want to install on some other machines, say your repository mirror.

This works:

rpm --import 'http://pgp.surfnet.nl:11371/pks/lookup?op=get&search=0xBF226FCC4EBFC273'

I wonder why this is different than the -newkey key. Anyway, don't take my word for it, check the signatures to prove it for yourself.

Apple's Snow Leopard (10.6) operating system is due out in the next quarter according to slides shown recently at the LISA conference. It adds a small handful of features but it's mainly an architecture, performance, and bugfix release. Leopard (10.5) is pretty buggy and Apple readily admits it's not what an OS should be. So they're coming out with an update less than a year and a half since the last one, which is by most counts what Leopard should have been. This isn't really disputed, even Apple's name isn't for a new cat, this is the one with all the 'marks cleaned off'.

OK, so it's great that Apple's getting everything squared away so quickly, right? Yeah, it is if you've got recent hardware.

But what if you have a computer that was purchased in, say, the first half of 2006? It's going to have a PowerPC processor in it, and Snow Leopard doesn't support PowerPC. OK, so then you can run Leopard, which does support PowerPC. But, wait, Leopard is buggy, that's why they're fixing it.

OK, so you can run Tiger (10.4). Well, no, if you're going to be connected to a network you'd be foolish to do that; Apple only issues security updates for the current and previous versions of its OS, and with 10.6, 10.4 will go by the wayside. Within months there will be public exploits for your 10.4 machine available and the time to your machine being compromised is just a roll of the dice.

"Wait," you may be saying, "my machine is less than three years old and it's now unsupported?" "It's still under AppleCare warranty and I can't even get security updates?"

Yep, and there we see the tactical brilliance behind splitting the Leopard and Snow Leopard releases - Apple gets to book its revenue early on a not-ready OS, beat Microsoft to the market, and save a ton of money really only supporting one majoor version of its operating system. So, this doesn't really work out well for you? Just buy a new Mac, they're probably not going to do this again in three more years. Right?

This may be a dangerous gamble for Apple in a recessionary economic period, so perhaps they'll do the right thing and simultaneously keep their customer base. If not, Ubuntu 8/PPC isn't eligible for a commercial support contract but it'll run on your Mac and its security updates will be current for another two years. At that point your machine will be five years old and you can keep it around with debian or netbsd or if we're coming out of the downturn get yourself a brand new machine. By then you'll be so used to Ubuntu you'll have broad purchase options.