Red Hat Network (RHN)
About a year ago, I did a review on Red Hat Network (RHN 4.0). RHN provides systems management services for Red Hat Linux, including the software that makes up the OS and the applications that run on your box. RHN helps you manage availability, performance and systems administration tasks. It includes patch management, OS deployment and the ability to deploy fully configured systems.
The Red Hat Network functions are delivered separately in the form of modules on a subscription basis. Available modules include an update module (automated patches and fixes), a management module (supporting systems administration and scheduling of activities) and a provisioning module (supports provisioning on bare metal systems and facilitates systems migration and monitoring) that also tracks systems performance, including CPU, RAM and I/O. The system itself is delivered in three options: a hosted service, a Satellite server (local server on your network) and a proxy server, where an RHN proxy resides on the customer network.
SUSE Enterprise Server ships with YaST and autoYaST, homegrown tools that help manage your Linux environment. YaST is now open-source and some third party companies have even provided "plug-ins" to help administrate their applications. For example, both SAP and Oracle have YaST plug-ins to help manage their environments.
To augment the services that YaST performs, Novell also sells a tool called ZENworks Linux management. ZENworks uses automated policies that give system administrators centralized control over Linux systems for the purposes of desktop lockdown, imaging, remote management, inventory and software management.
ZENworks also configures, updates and secures the environment from a centralized location. Further, it provides centralized logging and monitoring and allows you to access your systems via remote control. It supports almost every environment out there, including all the major flavors of Linux, Microsoft Windows, NetWare and several mobile platforms also. The Linux management tool is available as a standalone product or within the ZENworks Suite, bundled with Novell Linux Desktop or with SUSE Linux Enterprise Server 9.
Cost or flexibility?
Novell is currently trumpeting its lower total cost of ownership (TCO) and supposed ease of maintenance of ZENworks vs. RHN. While RHN offers the flexibility of providing more ways of using the product (ZENworks runs only on the customer premises), that flexibility comes with a price. ZENworks is clearly less expensive then RHN, coming in at a cost of $69 per managed system.
While all RHEL users receive access to RHN as part of their overall subscription fee, Red Hat charges separately for each of the service modules; including management, monitoring and provisioning. Each module costs an extra $96 or $192 per managed system. Some modules require the purchase of additional servers such as the Satellite server, which allows users to get the full functionality of RHN inside their firewall. The cost of the server is over $13k and it requires Red Hat professional services to install. Of course, one could purchase the RHN proxy instead, which would cost approximately $2500 for each server (per year).
RHN also provides support for Solaris and both tools provide replication ability for enterprise rollouts.
A new feature in ZENworks Linux Management allows one to image any Linux device with AutoYaST, KickStart or ZENworks imaging. AutoYaST and KickStart perform scripted Linux installations on your devices, but ZENworks imaging takes a snapshot image of a device and then restores the image to that or any other device.
ZENworks imaging is also the only method that provides add-on images. These are separate partial images of custom components that can be automatically added to the device. An example of this is that one can put unique sets of drivers or other files in companion add-on images, then group various sets of add-on images. At that point, you can then specify that ZENworks apply unique images to specific machines.
It's very easy to manage and control the imaging of your devices. First you must create an imaging bundle in the system, then you choose the type of preboot work you need. When that is done, you assign the preboot bundle to a specific device or group of devices and then use the ZENworks Control Center to apply the image the next time the device boots. You can also specify that an image be applied immediately through the ZENworks Control Center or you can send it into PXE and manually re-image the device.
It is in the ZENworks control center that you control your prebook services task. Here you have the flexibility to image many ways including the AutoYaST bundle, Kickstart, ZENworks image bundle, multicast bundle and the script bundle. The script bundle allows you to write custom scripts to automate operations.
To create the bundles, from the Control Center Interface, you would go to Bundles > New > Bundle > Preboot bundle. You would then select a bundle type. It's very intuitive and pretty much point and click. The inventory functionality is another very useful feature. From the control center, you just click devices and then inventory. From here, you will see information such as the last scan date, the MAC, IP and subnet mask information, as well as the hostname and any aliases that exist for the device.