How To Install Ubuntu 12.04 On Non-PAE Capable Hardware

Physical Address Extension (PAE) is a feature to allow (32-bit) x86 processors to access a physical address space (including random access memory and memory mapped devices) larger than 4 gigabytes.

Ubuntu 12.04 (as well as Kubuntu 12.04) uses the PAE Linux kernel by default for 32bit ISOs so old computers that don't support PAE can't boot the latest Ubuntu version. But there is a way to install Ubuntu 12.04 LTS Precise Pangolin on computers without PAE support: using the non-PAE netboot Minimal ISO (there are also some alternatives, see below).

The non-PAE netboot mini ISO lets you install the non-PAE kernel and the desktop environment you want: you can select to install Ubuntu Desktop (with Unity), Kubuntu Desktop and so on. One note though: since the minimal CD will download packages from online archives at installation time instead of providing them on the install CD itself, you need a working Internet connection during the installation.

Install Ubuntu 12.04 LTS on non-PAE capable systems using the netboot minimal ISO

Download mini.iso from HERE, write it on a CD or USB stick and boot from the ISO like with the regular Ubuntu ISO and select "Install":

The installer will now ask you a bunch of questions regarding the keyboard, etc. - select the options you want (use TAB to move through fields, SPACE to select and ENTER to activate buttons / continue). If you use a proxy, you'll be asked to enter it before the installation starts:

Basically, all the info available in the regular installer are also available for the mini ISO, like selecting your country, choose if you want to encrypt you home directory, partition the hard disk and so on:

After partitioning your hard disk, the installer will start downloading the core packages:

If some packages fail to download, you can select to continue and at the end of this step, you'll get to the Ubuntu Installer Main Menu where you can select "Install the base system" so the installer will try to redownload the packages for which the download failed:

Next, you'll be asked to select the Linux kernel you want to use - here, select "linux-generic":

The next important step is to select the desktop environment you want to use. Select it using the SPACE key (don't just press enter or else you'll end up with the core system only and without a graphical desktop environment!):

• for Unity, select "Ubuntu Desktop"
• for KDE / Kubuntu, select "Kubuntu Desktop"

Next, make sure you install the GRUB bootloader (by simply selecting "Yes" when you reach the screen below):

And that's about it, after you complete the above steps, you should have a working Ubuntu 12.04 LTS (with Unity or KDE) that runs on non-PAE supported hardware.

You can also watch a video with the whole non-PAE Mini ISO Ubuntu 12.04 installation process, below:

(Direct video link)

Alternatives

Like I was telling you above, using the non-PAE mini ISO isn't the only way to install Ubuntu 12.04 Precise Pangolin on computers that don't support PAE. You can also install Xubuntu or Lubuntu since both come with non-PAE Linux kernels, and if you don't want to use XFCE or LXDE, simply open a terminal and type:

- for Unity (and all the default Ubuntu packages):

sudo apt-get install ubuntu-desktop

- for KDE:

sudo apt-get install kubuntu-desktop

Update: there's also an unofficial non-pae Ubuntu 12.04 ISO available for download HERE (thanks to Bob for the tip!).

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Increased Performance In Linux With zRam (Virtual Swap Compressed in RAM)

While trying to optimize the elementary OS performance, Sergey Davidoff stumbled upon a project called compcache that creates a RAM based block device which acts as a swap disk, but is compressed and stored in memory instead of swap disk (which is slow), allowing very fast I/O and increasing the amount of memory available before the system starts swapping to disk. compcache was later re-written under the name zRam and is now integrated into the Linux kernel.

I decided to give it a try, and the result on my desktop with a quad-core CPU and 2Gb of RAM was fantastic: instead of freezing after running out of RAM, the system worked like nothing happened. I didn't notice any difference at all. It looked just like adding more RAM! Surprisingly, I got almost the same results on a 6-year-old laptop with Pentium M and 1Gb of RAM! So, I've improved the script to automatically adapt to the amount of memory in the system and automatically scale across several CPUs or CPU cores, packaged it in .deb and uploaded to PPA.

- Sergey Davidoff

Sergey also mentions that the only thing that prevents this from being enabled by default in elementary OS Luna for now is the existence of Atom netbooks with fast SSDs for which he doesn't know if this would be useful or not.


This is especially useful for netbooks, old computers (or computers that don't have too much RAM), virtualization or embedded devices but of course, you can use it on any computer.

To install Sergey's script in Ubuntu 11.04 or 11.10, use the following commands:

sudo add-apt-repository ppa:shnatsel/zram
sudo apt-get update
sudo apt-get install zramswap-enabler

If you don't want to add the PPA, you can manually download and install the .deb from HERE. The script should work with Linux kernel 2.6.37.1+.

If you're not using Ubuntu, you can download the script from HERE or get the source from BZR. This is an Upstart script so you need to place the "zramswap.conf" file under /etc/init and then start it using "sudo start zramswap". Please note that Fedora 15 has replaced upstart with systemd.

Update:

• For Fedora 15+ (which uses systemd instead of upstart), see: Enable Zram in Fedora
• For Arch Linux, see THIS comment (script converted to rc.d).

More about compressed caching for Linux:

• http://code.google.com/p/compcache
• http://weirdfellow.wordpress.com/2011/05/04/compressed-ram-with-zram/

Many thanks to Sergey for the tip and all the info!

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Linux Kernel Power Issue / Overheat Workaround

As you probably already know, the Linux Kernel has a pretty significant power issue starting with version 2.6.38 which hasn't been fixed yet (this includes version 3.0.0). This bug causes power consumption to go up by nearly 30% (and hence a shorter battery life) as reported by Phoronix which is pretty bad for netbook / laptop users. Some users are also reporting that this causes their laptops to overheat.

Well, Phoronix has found a way around this bug (you can read the article here) so below I'll tell you the exact steps you must follow to finally fix this issue.

The instructions below will force Active-State Power Management to be enabled by editing the GRUB2 config file and while this should work for most computers, it will not work for all. Also, Phoronix notes that "if your system's BIOS/hardware is in bad shape, you may hit system hangs" though it seems this is not something very common:

"I've never encountered ASPM problems with it enabled on any of my systems in pre-2.6.38 nor have I seen any reports of such in the Phoronix Forums or elsewhere."

- Phoronix

But anyway, use this at your own risk!

How to apply the Linux Kernel 2.6.38+ power issue workaround

1. To force Active-State Power Management to be enabled, you must edit the GRUB2 config file so open a terminal and copy/paste this:

gksu gedit /etc/default/grub

2. Then, locate the line that looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

(it's on line 11 on my computer) and to the end of the line, before the last quote, add pcie_aspm=force (and a space before it), which should make it look like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force"

Now double check you've edited the file correctly! Modifying this file incorrectly may cause your computer to stop booting!

3. And finally, update GRUB using the command below:

sudo update-grub

And restart your computer.

If something goes wrong, reverting the changes is pretty easy: simply open "/etc/default/grub" as root and remove "pcie_aspm=force" from the end of the "GRUB_CMDLINE_LINUX_DEFAULT" line, then run "sudo update-grub".

Thanks to Phoronix for the workaround and gnulinux.cat for the heads up!

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Deja Dup Gets Ubuntu One Support; Linux Kernel 3.0.0 Available In Ubuntu 11.10 [Oneiric Updates]

Michael Terry, the Deja Dup developer has announced that a recent update in Ubuntu 11.10 Oneiric Ocelot brings the promised Ubuntu One integration. Here are some screenshots:

This also means that Duplicity, the command line tool that powers Deja Dup supports Ubuntu One too. For now, Deja Dup is not yet default in Ubuntu 11.10 but this is expected to happen soon.

Unfortunately I couldn't test the actual backup feature because Ubuntu One (in Ubuntu 11.10) refuses to connect on my computer.

In other Ubuntu 11.10 Oneiric Ocelot news:

- LightDM is now default in Ubuntu 11.10, replacing GDM (by the way, it's default in Xubuntu too). But as expected, there's no greeter (theme) yet:

- Linux Kernel 3.0.0 has also made it into Oneiric:

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