Chapter 4 About Software Channels
Before you can use Spacewalk to provision client systems, you must first define software channels and populate them with software packages. You can configure Spacewalk to automatically populate packages from external repositories. Or, you can use the command line to manually push packages into a software channel.
From Oracle Linux 7 Update 1 onward and Oracle Linux 6 Update 9 onward, you do not need to install the Spacewalk client packages in order to register clients. However, Oracle recommends installing the Spacewalk client channel packages to take full advantage of Spacewalk's management capabilities, including provisioning and auditing. You also need to enable the Spacewalk client channel if you want kickstart to register a client automatically, as kickstart does not recognize the built-in client for this purpose.
There are a number of ways to populate the software channels that are created with packages. An easy way to populate a software channel initially, so that it can be used with kickstart, is to mount an ISO image on the server and use the rhnpush command to push packages from the ISO distribution.
Alternatively, you can synchronize channels from ULN or Oracle Linux yum server repositories by using the Spacewalk web interface. Or, you can use either the spacewalk-repo-sync or spacecmd command.
Before running the rhnpush command, the system that you are using must be registered with the Spacewalk server, even if the command is being run on the same system that is hosting the Spacewalk server. The rhnpush command uses the Transport Layer Security/Secure Socket Layer (TLS/SSL) protocols to communicate with the Spacewalk server. If the system is not registered, the rhnpush command fails with a certificate error. Client registration updates the configuration to use the correct Spacewalk SSL certificate. For more information about client registration, see Registering Client Systems in Spacewalk for Oracle® Linux: Client Life Cycle Management Guide for Release 2.7.
Differences Between ULN and Oracle Linux Yum Server Channels
ULN provides base and patch channels for each update of an
Oracle Linux release. The Oracle Linux yum server does
not provide separate patch channels.
Instead, it provides a olN_latest repository
that includes all of the packages for an entire release. See
Working With Software Channels in
Spacewalk for Oracle® Linux: Client Life Cycle Management Guide for Release 2.7 for further information.
Optimizing the Speed of Channel Synchronization
Because it can take several days to synchronize an Oracle Linux latest channel from the Oracle Linux yum server repository, populating base channels for an Oracle Linux release from an ISO image is generally faster than pulling the base packages from an upstream repository.
After you have created and initially populated channels from an ISO image, you can synchronize them with the Oracle Linux yum server and ULN to bring them up to date. The Oracle Linux yum server is mirrored on a number of servers globally, so it can be faster to synchronize the base channels with the Oracle Linux yum server and subsequently synchronize any patch channels with ULN.
If you specify the --latest option with the spacewalk-repo-sync command or select the equivalent optional check box in the web interface, the server synchronizes only the latest packages that are available at the time of synchronization. The process does not remove older packages from the channel. If the synchronization interval is large, you might miss a particular version of a package, which can have implications for errata handling, where errata are associated with specific package versions. If errata consistency is important to you, Oracle recommends that you do not select these options. Note that using the --latest option with a Ksplice channel is an exception to this rule because its packages are always cumulative.