Changing drive names

Q I have a problem with recompiling a 2.6.22 kernel to be used on my Mythbuntu 8.04.1 setup. I use a Hauppauge HVR-1300 TV card and have discovered by trial and error using Debian Etch that all kernels greater than 2.6.22 cause problems with digital reception when tuned to 506 and 562MHz from the Crystal Palace transmitter in the UK. This means that I can't receive all the BBC and Five channels, the audio stutters and the picture is full of large pixels. All the other frequencies are unaffected.

Mythbuntu 8.04.1 uses kernel 2.6.24, but when I compiled a 2.6.22 kernel using sources from both kernel.org and Ubuntu, it failed to boot because Ubuntu uses the sda, sdb numbering scheme to define its hard drives, and the recompiled kernel expects the numbering scheme to be hda, hdb and so on. I have tried changing the root=/dev/sdb3 to hdb3 in Grub's menu.lst and changing the fstab entries and got the kernel to boot, but none of the TV applications can get a signal lock! I've also tried using root=UUID=hexnumber to define the root drive, but that also failed.

Is it possible to compile the kernel so that it recognises the Ubuntu numbering scheme, or have the Ubuntu devs patched their sources so that it's not possible to use a vanilla kernel?

A You should be able to use the sd* naming of your hard drives with a 2.6.22 kernel as this option was added around 2.6.19. That was when the CONFIG_ATA option was added, you'll find it at Device Drivers > Serial ATA (prod) and Parallel ATA (experimental) drivers. You need to enable this option and pick the driver for your motherboard chipset. You must also disable ATA/ATAPI/MFM/RLL support (CONFIG_IDE) that handles IDE drives the old way. Start configuring the kernel by copying the .config file from your existing kernel into its directory and run

make oldconfig

This will prompt you for settings for any changed options and leave the rest as they were, ensuring maximum compatibility. You can always run make menuconfig or make xconfig after this to tweak the settings.

However, what is the most recent kernel you've tried? There were some fixes in the 2.6.28 kernel that related to DVB (as used by digital TV). There have also been changes in the V4L (Video4Linux) part of the kernel that may affect the analogue side of your card. It may also be worth upgrading your Mythbuntu to 8.10, to get the later, hopefully more compatible, versions of everything.

You don't need to reinstall to do this. Open Synaptic Package Manager and choose Settings > Repositories. Go to the Updates tab and set "Release Upgrade" to "Normal Releases". Close Synaptic and open the Update Manager, which will tell you "New distribution release 8.10 is available". Click Upgrade and follow prompts to upgrade your system to

the latest 8.10.

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