Jaunty HOWTO

Posted on July 16, 2009

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A few weeks ago, I traded my Fujitsu S6240 to a friend for his Aspire One. It might seem like I got the short end of the stick but I wanted something much, much smaller than my Fujitsu for carrying on the train to and from work. My friend wanted something larger since he only uses it in his living room and occasionally carries it up to his rooftop deck.

This page relates my experience with installing Linux on an Aspire One ZG5 (A.K.A. AOA110). More specifically, my efforts to install and tweak Crunchbang Linux (an Ubuntu derivative). My sources of information included the following:

The following instructions will work for the Aspire One ZG5 and to some extent, the other Aspire One models and should be relevant for any Ubuntu derivative.

The specs of my Aspire One are:

  • 8.9″, 1024×600 display
  • 1.6Ghz Intel Atom CPU
  • 1GB ram
  • 16GB SSD

Installing Crunchbang

To start with, I started my install of Crunchbang linux 9.04.01 by first installing a command line Ubuntu system using the Jaunty minimal install iso that I flashed onto a USB stick using unetbootin. Of course you need either a wired internet connection or else a wireless connection and possibly some command-line-fu to use the mini.iso.

I created / and /home partitions using the relatively old ext2 filesystem with mount option noatime instead of the default relatime and did not create a swap partition. My use of ext2 and the lack of a swap partition are because I have an SSD and want to minimize disk writes to extend its life. More modern filesystems use journaling which log filesystem writes to a journal. This reduces the likelihood of filesystem corruption but comes at the expense of additional writes to the drive. I do later enable swap using an SD card but there probably would have been no harm in creating a traditional swap partition since my Aspire One rarely (if ever) swaps.

I then completed the install using the Crunchbang 9.04.01 install script. After downloading the script type:

sudo bash crunchbang-installer-9.04.01.sh

type your password, select the type of install you want and then enter ‘y’ when asked whether or not to install the medibuntu keyring. It will run for a while, depending on your connection speed. Near the end of the install, it will ask you if you want to use network-manager. I chose not to since I prefer wicd to manage my internet connections.  If you want to use wicd, answer no when the script asks you if you want to reboot and type:

sudo aptitude install wicd

After that, reboot into your new system by typing ‘sudo reboot’.

Note: Since the time I installed Crunchbang, 9.04.01 was officially released and one can instead install using a flash drive, unetbootin and your preferred i386 crunchbang or ubuntu variant iso.

SSD optimization

Because I have an SSD, my first tweak upon completing my install was to optimize my filesystem to minimize writes to the drive.

To start with, I wanted to put /tmp and /var/tmp into ram so that temporary files are not written to the drive. To do so, fire up your favorite text editor and add:

tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
tmpfs /var/tmp tmpfs defaults,noatime,mode=1777 0 0

to the end of /etc/fstab.

Next, I also wanted to put /var/log and /var/cache in RAM. The typical way I’ve seen this done is to duplicate the above lines for /var/log and /var/cache and then modify the /etc/rc.local script to recreate the directory structure. A more elegant approach, in my opinion, is to mount them as unionfs read-only along with /tmp. This preserves the existing directory structure but any changes are written to RAM. To do all this I added:

none /var/log unionfs dirs=/tmp:/var/log=ro 0 0
none /var/cache unionfs dirs=/tmp:/var/cache=ro 0 0

to the end of /etc/fstab. At this point you may reboot if you like to make these optimizations active.

The next SSD optimization I applied is to add ‘elevator=noop’ to the defoption line of /boot/grub/menu.lst, i.e.,

# defoptions=elevator=noop quiet splash

and then to run ‘sudo update-grub’. The various ‘elevator’ kernel options specify the order in which writes are made to a disk. This is important for traditional hard drives where the write head moves along the platter and writing sequentially according to the direction the write head is moving will improve performance. But with an SSD, there is no write head so that specifying a particular order for writes can actually degrade performance. The ‘elevator=noop’ kernel option disables this, improving SSD speed.

Note: One might be tempted to do the SSD optimizations before running the Crunchbang install script but unless you do this right, you will run out of space on /tmp and quite possibly bork your install. To truly minimize SSD writes, one could do all of the SSD optimizations and then comment out the /var/cache line of /etc/fstab until after the install is complete.

As mentioned earlier, I did not create a swap partition on the main drive because I did not want unnecessary writes to the SSD. However, I have a 128MB SD card that came with my GPS (and who uses those anymore) and is essentially useless in a world where 4GB and 8GB SD cards can be had for cheap. So I popped it into the lefthand SD card slot, formatted it as swap and mount it by adding:

/dev/mmcblk0p1 none swap sw

to /etc/fstab. A gig of RAM seems to be more than enough but given that I have no use for a 128MB SD card, using it as swap can’t hurt.

Firefox on an SSD

Firefox by default caches data to the hard drive. This is no good for an SSD but it can be fixed by telling Firefox to cache data in /tmp. To do so, open Firefox and type ‘about:config’ in the browser window. Click ‘I’ll be careful, I promise!’ and then create (or edit) the key ‘browser.cache.disk.parent_directory’ and give it the value ‘/tmp’.

Kernel

There are also a number of choices in terms of alternative kernels (Array.org, AspireOneKernel.com, Kuki Kernel, etc). I found that none of them were as stable as the stock Ubuntu kernel. Moreover, the Ubuntu kernel now boots so quickly (30s to the GDM login screen), it is not clear to me what the advantage of these custom kernels is. Mind you, I have not timed my boots but from my own observations it seemed to me that the ranking of boot speeds, sickboy’s kernel is fastest followed by the kuki kernel and finally the stock ubuntu kernel. That said, my guess is that the difference in boot times is in the neighborhood of only 2-3 seconds.

Fan speed management

Fan management by the Aspire One’s bios sucks. To fix this, I installed the acerhdf kernel module. To do so, type:

sudo aptitude install build-essential linux-headers-generic
wget http://www.piie.net/files/acerhdf_kmod-0.4.0-3.tar.gz
tar xvf acerhdf_kmod-0.4.0-3.tar.gz
cd acerhdf_kmod
make
sudo make install
sudo modprobe acehdf

You can get the most recent version here. Also, you will need a different version if you decided to install a 2.6.30 or later kernel.

Wireless

Over several weeks of experimentation, the stock ath5k driver module appears to be less than stable, sometimes dropping the connection and in fact losing the interface altogether. The only way to bring back the interface is to completely shutdown and then do a cold boot — simply rebooting, in my experience, does not work. Because of this, I compiled and installed the madwifi_hal driver as suggested in a couple of the pages mentioned above. To do so, type:

wget http://snapshots.madwifi-project.org/madwifi-hal-0.10.5.6-current.tar.gz
tar xvf madwifi-hal-0.10.5.6-current.tar.gz
cd madwifi-hal-0.10.5.6-r4068-20090705
make
sudo make install

Get the most recent version here. Wifi should be working quite stably after a reboot although you may need to blacklist ath5k. These wikis also explain how to modify /etc/sysctl.conf to get the wireless LED working (note that this tweak only works with the madwifi_hal driver, not the stock ath5k driver). This seems to cause problems for suspend (which is somewhat unreliable anyway), resulting in a hard freeze which requires a forced shutdown and cold boot.

Edit 8/22/09: the latest kernel (2.6.28-15-generic) seems to have fixed any wireless instability issues with the ath5k kernel module. This has the added bonus that suspend now works flawlessly. The only cost is that the LED no longer works.

Edit 8/25/09: The following workaround gets you wireless ath5k with the LED working.

sudo aptitude install linux-backports-modules-jaunty

Create /etc/modprobe.d/blacklist-ath.conf and add:

blacklist ath_pci
blacklist ath_hal
blacklist acer_wmi

Reboot and wireless should be working with a blinking LED. And suspend works!

Sound

Sound works out-of-the-box with the stock kernel but to get the microphone working without large amounts of static, I had to create an /etc/modprobe.d/sound file and add:

options snd-hda-intel model=acer-aspire

Hardware hacks

It is possible to add RAM and internal bluetooth, swap out the drive, add 3G wireless and add eSata to the Aspire One ZG5. These mods are of varying degrees of difficulty but none of them are as simple as unscrewing a bottom panel and popping in the new hardware. In particular, all of them require opening up the laptop, removing the keyboard and then removing the motherboard and the latter two mods require some difficult soldering (according to tnkgrl herself).

In my case, 1GB of RAM seems to be sufficient for my needs. While the stock SSD is on the slow side (after logging in, a few seconds pass before I can do more than open claws-mail), I’ll only swap it out if and when the current drive crashes. Given that some bluetooth dongles are so tiny these days, I don’t see any reason not to leave one plugged in at all times. And for me at least, 3G and eSata seem a bit excessive.

Final thoughts

There may be other tweaks that I’ve applied but don’t remember. Please comment if you spot any errors or have suggestions. I will make additions and modifications as necessary.

Posted in: HOWTO, Jaunty