Anaconda Updates
anaconda has the capability to incorporate updates at runtime to fix any bugs or issues with the installer. These updates are generally distributed as a disk image file (referred to as updates.img from here on out). The updates.img can be used in a few different ways.
Updates types
There are a number of sources for the updates.
Updates from the Network
The easiest and most popular way to use an update.img is via the network. This is how almost all updates images you'll see in bug reports and mailing lists are distributed. This does not require you modify your installation tree at all.
To use this method, simply boot with:
linux updates=http://some.website.com/path/to/updates.img
If you have multiple network interfaces, anaconda will first prompt you to select one (unless you have used the ksdevice= boot parameter). It will then attempt to configure this link using DHCP. If you require other networking configuration, you will need to use various options. ksdevice= can be used to specify a different network device, and the ip= option (along with others for gateway, nameserver, and so forth) can be used for static configuration. All anaconda config options are described elsewhere .
If you are making your own updates.img, just upload it to a web server you have access to and pass the location as above.
Updates from a disk image
You can also put an updates.img on a block device (either a floppy or a USB key). This can be done only with an ext2 filesystem type of updates.img. For a floppy drive, insert your floppy and then run
dd if=updates.img of=/dev/fd0 bs=72k count=20
to put the contents of the image on your floppy. Then, boot the installer with
linux updates
and you will be prompted to provide the location of your update disk.
You can also use a USB key or flash media -- just replace /dev/fd0 with the device that your USB key is at.
Updates from the Tree
If you're doing a CD, hard drive, HTTP, or FTP install you can also put the updates.img in your tree to be picked up by all installs automatically. Put the file in the images/ directory.
For NFS installs, there are two options. You can either put the image in images/ as above or explode the image into the RHupdates/ directory in your installation tree.
How to Create an Anaconda Updates Image
If you are working on anaconda or looking at a bug and want to test your own bug fixes, it's easy to create your own updates.img file. anaconda supports two formats: an ext2 filesystem image and the more common gzip-compressed cpio archive. The automatic tools shipped with anaconda deal in the second form, so that's what will be discussed here.
The easiest way to create an image is to run
make updates
from the anaconda source tree. This will package up all the changes to the tree since the last release and create a file named "updates.img" in the top of the tree. If you need finer control over this process (like creating an image from an even older release), run
scripts/makeupdates
by hand. The help screen documents the several options that can be used.
An updates.img can include more than just files from anaconda, though. It can also include shared libraries, graphics, other python modules, and certain data files used by anaconda. To add files to an existing image (or create an entirely new one), just do the following:
scripts/upd-updates updates.img file1 file2 ...
Note that the placement of files in an image is a little picky. For instance, python modules must be in their proper subdirectory mirroring the layout of /usr/lib/python?.?/site-packages/.
How to Examine an Anaconda Updates Image
updates.img files provided by the Fedora project are compressed cpio archives. To examine one of these files, use /sbin/lsinitrd.
To explode one, do the following:
$ mkdir dest $ cd dest $ gunzip -dc /path/to/updates.img | cpio -id