ITS manages the UI Spacewalk service.  CentOS is a free version of Linux and can be used in place of Red Hat when commercial vendor support is not a requirement.  Any University department managing CentOS client or server systems may request access to Spacewalk for software updates. 

The UI Spacewalk service is scoped to systems on the University campus. Systems such as laptops must be on the University network to receive updates.

For more information, contact the ITS Spacewalk team at

To use Spacewalk, you need a departmental activation key. A departmental activation key provides access to the appropriate OS software and places your system into your departmental system group. Customers should check with their departmental IT support to determine if an activation key has already been issued. If not, the department IT may request one by contacting

To register your system using your departmental activation key, type the following commands:

/usr/bin/yum install rhn-setup

/bin/rpm -Uvh

rhnreg_ks --serverUrl= --sslCACert=/usr/share/rhn/RHN-ORG-TRUSTED-SSL-CERT --activationkey=<departmental activation key>


To properly communicate with Spacewalk, the rhnsd daemon should be running on client systems. The rhnsd daemon is responsible for periodically checking in. 

To verify on CentOS 6:

chkconfig --list rhnsd

service rhnsd status  

To verify on CentOS 7 or Fedora:

systemctl list-units rhnsd.service

systemctl status rhnsd.service

If you have console access to, you may log in and manage  any system by browsing to the system, choosing the Software tab and then choosing the Software Channels tab. You'd then make any adjustments as needed. This can also be done for multiple systems via the System Set Manager.

If you prefer to use the command line, ensure the rhn-setup package is installed and then use the spacewalk-channel command. See the system manual page for more information.


If you have questions or require software not listed, contact

CentOS repositories (repos) within the active lifecycle are available, e.g. CentOS base, updates, extras, scl_rh, centosplus

Fedora Linux (the currently supported server and workstation) are available.

Selected third-parties repositories are also available, e.g., Puppet, EPEL.

If you have questions or require software not listed, contact

ISO images for the latest version of CentOS/Fedora are available via the ITS Mirrors Service at

If the software or hardware distribution you require isn't listed, send an email to  Please include complete software and hardware version information (e.g., CentOS Linux Server version 7.6).

The UI Spacewalk service does not support source RPM download, however source RPMs are available from the respective vendor's or project's web sites.

The UIOWA-LINUX-ANNOUNCE mailing list is used to provide notices concerning Linux services managed by ITS. When access is granted to Spacewalk, the departmental contact will be added to this list. Any University person managing systems with Spacewalk may contact to be added to the mailing list.

The UI Spacewalk service  is considered an 9am-5pm/M-F service. In the event of a catastrophic failure, recovery time may be hours or days, depending on the problem.

Problems may be reported to or

Spacewalk has a standing weekly downtime window of 12:00 p.m. to 5:00 p.m. every Monday afternoon. The Spacewalk team may or may not use this window to perform maintenance. The Spacewalk team makes a best effort to notify customers (via the UIOWA-LINUX-ANNOUNCE@LIST.UIOWA.EDU mailing list) of planned work during this maintenance window; however, we advise customers to plan their own system maintenance outside of this window.

Errata for CentOS is the same as what Red Hat posts at The packages are just delayed while the changes process through the CentOS infrastructure.

Because CentOS is community supported, there is not a central repackaging of the errata information for ready consumption by Spacewalk. Listing of errata information via yum has not been 100% reliable. Generally, the advice is to apply all updates rather than picking up only security related updates. You can subscribe to the CentOS-announce mailing list at for the most current errata news. The emails from that list will have links to the RedHat errata notices.

On a client system, the yum list-sec command provides information on outstanding errata (when the errata is current).

Details on a particular errata may be found on Red Hat's web site. For example, to see details about CESA-2019:1168, visit

When a client system stops checking into Spacewalk, it becomes inactive after a few days. This may happen when a system is decommissioned, rebuilt, or moved off campus temporarily. Any client system that is inactive for more than six months is removed from Spacewalk.

If you wish to have a client system removed sooner, contact

If you have console access, you can log in to, browse to the system, choose Delete System.

Otherwise, send an email to

Client systems subscribed to the Spacewalk service check in periodically to determine pushed updates, subscriptions changes, etc. If you wish to force the check-in to happen sooner, run this command as root on the client system:

yum install rhn-check #One time only to install the program


University customers managing Spacewalk systems are automatically provisioned login accounts on Spacewalk when access is first requested. If administrators change or need to be added, send a request to with the appropriate Hawk IDs and departmental activation key names.

To log in, visit and provide your Hawk ID and password. (Authentication is via the IOWA AD domain only.)

Service level Agreement:

Hours of availability: 9-5 weekdays except during patch cycle

Patching Cycle:  Mondays from 12:00PM - 5:00PM

Article number: 
Last updated: 
May 20, 2019