Yum
Package Manager
Yum is Yellowdog Updater, Modified, a tool for managing Red Hat rpm packages.
To install a particular RPM on the XO, in a terminal enter
sudo yum install package name
package name refers to the specific name of the software to be installed. For example, installing a common web server, the package name might be apache-1.3.9-4.i386.rpm
For more on yum, on the XO, enter
yum -h
On other Linux systems that have "man", enter
man yum
or on many Linux system that use "yum" and "info", but only if you are familiar with "info" or "emacs", enter
info yum
Documentation
Note: To save space, OLPC OS images are configured to not extract documentation from rpm packages to the file system. If there is a specific package for which you might want this overturned, edit the file:
/etc/rpm/macros.pilgrim
and change the line:
%_excludedocs 1
to:
%_excludedocs 0
before installing it. Remember to switch it back after you are done.
Making persistent changes
By default, any packages you install with yum will be removed during the next update, since our update mechanism always aims to provide a clean system install.
If you want to install packages that will persist across updates, first obtain a developer key. Then, as root:
# yum install yum-utils
Then, as the olpc user:
$ mkdir -p /home/olpc/.custom/rpms $ cd /home/olpc/.custom/rpms $ sudo yumdownloader --resolve <pkgname> $ sudo rpm -Uvh *.rpm
This will download the RPM files needed to install <pkgname> into the ~olpc/.custom/rpms directory. When you upgrade to a new build, on first boot the olpc-configure program will check your developer key and then install all the RPMs found in that directory.
This is handy in order to ensure (for example) that emacs is always installed on your builds.
If you use this feature a lot, you may find it more convenient to create subdirectories under ~olpc/.custom/rpms for each major program you install, so that you can more easily keep track of which rpms go which what program. The first boot installation will look through all of the subdirectories of ~olpc/.custom/rpms to find RPMs it should install.
(Note also that if you wish to make regular additions to the .custom/rpms directory that you'll probably want to put the yum-utils rpm itself into that directory, so that yumdownloader is always available.)
See <trac>6432</trac> for more discussion of this feature. This code was written for the 8.2 release and first appeared in joyride-2106. It is not present in 650 (7.1), 653 (7.1.1), 656 (7.1.2), 703 (8.1), 708 (8.1.1), 711 (8.1.2) or 714 (8.1.3).
Tips
Memory Limitations
Yum is slow and memory-hungry on the XO-1. From devel.lists.laptop.org, "if we disable by default the fedora repositories, yum runs really quickly and does not download too much metadata." A command to do this is:
yum --disablerepo fedora --disablerepo updates -y update
On recent builds leading to release 10.1.3, there may not be enough memory to use yum. You can adapt to this by:
- adding swap space on SD card or USB, to free memory when pressure is detected,
- unmounting some of the tmpfs filesystems, to free memory by moving temporary files to the root filesystem, especially /var/cache/yum,
- stopping Sugar with the command stop prefdm in a terminal, to free memory being used by Sugar, or;
- stopping Sugar by switching to runlevel 1.
Unmounting /var/cache/yum will mean that the yum data will be saved permanently to the XO's storage. You should consider manually removing the files (rm -rf /var/cache/yum/*) after you are done, before you reboot.
Stopping Sugar using stop or switching runlevel will cause any network connection mediated by Sugar to be terminated, so you may need to manually establish a network connection using shell commands before attempting a yum command that requires network access.
Removing Dependencies
When you try to remove packages with yum, it doesn't remove the dependencies. Here is a script that helps you to keep track of those dependencies by logging the outputs of yum.
#!/bin/bash f=/home/olpc/yumlog/`date +%y-%m-%d`.txt echo ========================== | tee -a $f echo yum $* | tee -a $f echo -------------------------- | tee -a $f /usr/bin/yum-real $* | tee -a $f && exit 0 echo "??!!" | tee -a $f echo -e \\n \\n \\n| tee -a $f
Rename /usr/bin/yum to /usr/bin/yum-real, save the script above as /usr/bin/yum and create a directory called /home/olpc/yumlog. Unfortunately "tee" is buffered so you can't see the download-bars and the yes-no-prompt.
External References
- Managing Packages with Yum - including finding installed packages, and searching for more
- Yum HOWTO
- Yum repositories
- Setting up the Yum Client