The new Wacom Bamboo Pen (CTL-460) doesn’t work in Ubuntu Lucid out-of-the-box. You need a newer kernel module than the one that comes with Lucid by default. It’s pretty easy to get it working though, you just need to know how. Continue reading
Feel insecure about your data? Don’t trust your harddrive anymore? Use this howto to migrate your running Ubuntu Linux system to software RAID 1.
Before starting off, I assume you have your running system on /dev/sda and your new harddrive is called /dev/sdb.
Boot up your system and install the mdadm package. We now have to create partitions on sdb that are the same as sda. Because I have identical disks, I just copy the partition table from sda to sdb like so:
sfdisk -d /dev/sda | sfdisk /dev/sdb
After that, I use partprobe to let the Linux kernel know I have changed the partition table.
Next step is to create a degraded RAID array on sdb which we can copy the files to and than add sda to the array. For every partition you have to run:
mdadm --create /dev/md0 --level 1 --raid-devices=2 missing /dev/sdb1
Where you replace sdb1 with the partition you want. Now create filesystems on these new raid devices:
Again, run this for all your mds.
After copying all the files to your new array, we have to modify a few files.
All these files contain references to UUIDs that are no longer correct. I simply replaced them with /dev/md0 for example. You can try to use UUIDs, but I believe that the (striped) partitions have the same UUIDs as the raid devices (the mds). If you’ve changed everything, run:
mdadm --detail --scan >> /etc/mdadm/mdadm.conf
And don’t forget to update your initrd:
That’s all! You can now enjoy the safety of RAID 1 without to much hassle. To check the status of your array, look in /proc/mdstat. Also make sure you setup a mail server or ssmtp, because the mdadm tools will try to send you an email if one of your RAID devices is degraded/corrupt.
Another post about that Pinnacle DVB-T stick? No, this one is about the remote! I wrote that the remote wasn’t completely working yet. Apparently, there is a driver for this remote or the stick that converts the buttons from the remote to “keyboard events”. Meaning I can type the number 0-9 with my remote for example. However, the “change channel” buttons appear to send a keycode that is above 255 and the X11 protocol only reserves one byte for keycodes. This means those keycodes can’t be send to the X11 server and will disappear. There’s a bug about this in the X.org bugzillay: http://bugs.freedesktop.org/show_bug.cgi?id=x11-keycode-limit and their solution: Change the X11 protocol (meaning: start development on the X12 protocol) or remap those keyevents somewhere between the kernel and X.org. I think the last solution is probably the simplest. I only have to figure out how to remap those keys with hal.
Yesterday I decided to buy the Pinnacle DVB-T Stick (also known as Pinnacle TV Stick 72e) to watch some free-to-air channels. In the shop I searched on Google for Linux support, to make sure I didn’t have to return the product. The first few hits seemed positive (2 years ago), so I decided to take the plunge.
After arriving at home, I plugged the device in an empty USB port and saw this in my dmesg:
[11906.080060] usb 1-6: new high speed USB device using ehci_hcd and address 5
[11906.214249] usb 1-6: configuration #1 chosen from 1 choice
[11906.245886] dib0700: loaded with support for 8 different device-types
[11906.246212] dvb-usb: found a 'Pinnacle PCTV 72e' in cold state, will try to load a firmware
[11906.246222] usb 1-6: firmware: requesting dvb-usb-dib0700-1.20.fw
[11906.252816] dvb-usb: downloading firmware from file 'dvb-usb-dib0700-1.20.fw'
[11906.471526] dib0700: firmware started successfully.
[11906.972059] dvb-usb: found a 'Pinnacle PCTV 72e' in warm state.
[11906.972135] dvb-usb: will pass the complete MPEG2 transport stream to the software demuxer.
[11906.972367] DVB: registering new adapter (Pinnacle PCTV 72e)
[11907.186126] DVB: registering adapter 0 frontend 0 (DiBcom 7000PC)...
[11907.369975] DiB0070: successfully identified
[11907.370122] input: IR-receiver inside an USB DVB receiver as /devices/pci0000:00/0000:00:12.2/usb1/1-6/input/input12
[11907.396132] dvb-usb: schedule remote query interval to 50 msecs.
[11907.396140] dvb-usb: Pinnacle PCTV 72e successfully initialized and connected.
[11907.396744] usbcore: registered new interface driver dvb_usb_dib0700
Great! All drivers and firmware load automatically in Ubuntu 9.04 Jaunty.
Next step: actually getting video on my screen. After Googling I found out I first had to scan for channels using dvbscan. However, it gave me the non-informal message “Unable to query frontend status”. Apparently there is also another scanning program called scan. I ran it like this:
scan /usr/share/dvb/dvb-t/nl-All > ~/.mplayer/channels.conf
Now I could start mplayer dvb:// and enjoy watching DVB-T digital television! Note you can switch channels with h (next) and k (previous). Last thing I need to figure out is how to use the remote for this (I can change the volume already).
This post is just for the sake of documenting this.
A while ago I came across a blog post written by an Ubuntu developer (I believe) which gave a nice tip on how to boot a livecd in KVM without VNC. Yesterday I needed this feature again, but was unable to find it.
I needed to boot a hardy-jeos livecd on my server, but didn’t want to go through the hassle of punching a hole in my firewall and installing a vnc client on my desktop computer. Luckily this is not needed, because you can get kvm to output it’s serial console to your console (in combination with GNU Screen this is very usefull) and the livecd support serial console also. To do all this you just need to append this to your kvm startup command:
-nographic -kernel /mnt/install/vmlinuz -append console=ttyS0,9600 -initrd /mnt/install/initrd.gz -cdrom /home/frank/hardy-jeos-i386.iso
Of course, the relevant files should be changed according to your system. Note that the kernel and initrd files are on the cd, so you should mount the cd on the host sytem also.
Any questions? Just leave them in the comments!
I’ve been testing Ubuntu Jaunty for a few weeks now and after using it for a day or two, my memory filled up. Recently I found out that this was caused by Compiz. Apparently if you use UXA with the new Intel drivers, Compiz will start to leak memory. After only 8 hours of usage, Compiz was using more than 1.5GB of memory! The solution? Disable Compiz, because UXA is a big performance improvement for me.
Update: Apparently this bug is fixed (#328232).