Bodhi uses a semi-rolling release cycle. Major version releases mark a core component change (for example, a new kernel) but not an overall system rethink as is the case in many other distributions. Changes in Bodhi will be incremental and you will never need to do a major system update.
However, to keep your system “fresh” with the most recent software available follow these simple steps:
sudo apt-get update
This will download the list of currently available packages.
sudo apt-get dist-upgrade
This command will first display the list of packages for which newer versions are available. You may accept the entire list by entering “Y”, or decline with “N”.
You can install individual packages with the command
sudo apt-get install <package-name>
<package-name> with the actual name of the package) or by GUI with Synaptic Package Manager.
For a complete update from Bodhi 1.1 to Bodhi 1.2 see Bodhi 1.2 Upgrade.
Kernel updates are not included in the usual sudo apt-get upgrade process, this is because some people may wish to delay or not update at all to the latest kernel. There are rare occasions where a kernel update can cause problems, but overall they are usually safe.
The Bodhi developers try to build and add the latest Kernel builds to the repository soon after it becomes available, but to update to it you must do it manually. By far the easiest way do so is to visit the Linux Kernel page on Bodhi's AppCenter.
If you prefer to do this manually open Synaptic and click on the search button and do a search for linux-image, find the kernel you wish to install and install it. Note: if you have more than 4 gigabytes memory and want to be able to use it all you need the pae kernel:
If you prefer the command line:
To determine the your current kernel version:
Next find available kernel images:
sudo apt-get update apt-cache search linux-image
Once you have determined the kernel image you wish to install:
sudo apt-get install linux-image-x.x.xx-x-*
Where x.x.xx-x is the kernel version number and * is either generic or generic-pae. For example, the command below will install the latest kernel for x86/x86_64:
sudo apt-get install linux-image-2.6.39-2-generic
Or for the pae version:
sudo apt-get install linux-image-2.6.39-2-generic-pae
If for some reason you also need the Kernel header files:
sudo apt-get install linux-headers-$(uname -r)
If you are uncertain as which kernel image you need ask on the forums.
It is always a wise idea not to uninstall the old kernel when one first updates to a newer version. The new kernel will not overwrite the old and you will still be able to boot into the old kernel by selecting it at the grub menu. If the new kernel causes any issues you will be able to boot into the older kernel.
Here are some tricks I use regularly to keep my system fresh:
sudo apt-get update && sudo apt-get upgrade && sudo apt-get autoremove && sudo apt-get autoclean
This command updates your repository lists, upgrades packages if possible, and checks whether there are any packages or files to remove.
I also use bleachbit sometimes to clean my system. Install bleachbit via Synaptic or with this command:
sudo apt-get install bleachbit
Another tip can be to reduce/increase swappiness. Swappiness is a system variable which tells your system how to divide the memory load (how likely it is to move processes to the swap memory). If you reduce swappiness your system will take as much advantage of your 'real' RAM as it can before moving to swap which increases the speed (since RAM is faster than swap). This can be done editing the file /etc/sysctl.conf:
To open the file in nano (a terminal based text-editor) use this command:
sudo nano /etc/sysctl.conf
Or to use any other editor (leafpad is an example):
gksudo leafpad /etc/sysctl.conf
Then change the value of vm.swappiness (alternatively add this line):
If you did this in nano press CTRL+O to save and CTRL+X to exit. The changes to swappiness take place after rebooting.