How network services are used plays a big role in the success of the overall deployment. Ensure that you understand this area very well and involve the right people in the project from the start.
Individuals and departments that you want to notify and involve include:
Network services: The teams that manage the physical network infrastructure and hardware.
Security services: The teams that manage the security aspects of the network infrastructure and services.
Operations: The teams that manage the provisioning of services and resources to the devices that ZENworks Configuration Management will manage.
The following sections contain more information:
When considering the requirements for infrastructure, it is important to look at the available bandwidth for a workstation, in addition to the requirements of the management product. It might be necessary to update all devices as soon as possible.
By reducing the amount of infrastructure in place, ZENworks Configuration Management becomes more reliant on the available bandwidth to each device when deploying software.
To calculate the available bandwidth for a given site, a number of formulas can be used. The following examples indicate the amount of data that can be transmitted to a device within a given one-hour period. The formula assumes that a local Satellite device is not present. Therefore, all software downloads must be served by the WAN link to a Primary Server. Although these formula are not completely accurate, and are based on a number of assumptions, they can be used to indicate which sites are good candidates for a Satellite device. As a rule of thumb, most remote sites are good candidates for a Satellite device because your goal is to always deliver content and collect information from managed devices quickly and efficiently. Generally speaking, delivering content across a WAN infrastructure to multiple managed devices is not an efficient use of network resources.
The following formula defines how to calculate the maximum amount of data that can be transmitted to a device within a given one-hour period:
The result of this formula provides information on the amount of data that can be transmitted to each device within a one-hour period.
Available bandwidth in this formula is not the total link speed. Other data is transmitted over the link within a given hour and must be taken into account, for example:
File and print
Line of Business applications
In the following examples, sites with different numbers of devices and link speeds are used to demonstrate the levels of bandwidth available to a device within a one-hour period.
Two sites have been chosen: SITE 1 (650 devices with a 100 MB link) and SITE 2 (20 devices with a 10 MB link). For the purposes of the calculation, the formula assumes that approximately 95 percent of the available bandwidth is being used by other applications.
Based on link speeds, number of devices, and assumed available bandwidth, the formula gives the following results for SITE1:
In a one-hour period, it is possible to transmit 3.46 MB to every device at SITE 1 if you use all of the bandwidth available to ZENworks Configuration Management. This site, because of its size and lack of bandwidth per device, should be considered as a candidate to host a Satellite device.
Based on link speeds, number of devices, and assumed available bandwidth, the formula gives the following results for SITE2:
In a one-hour period, it is possible to transmit 11.25 MB to every device at SITE 2 if you use all of the bandwidth available to ZENworks Configuration Management. In this situation, you might not choose to place a Satellite device at this site because the level of bandwidth per device is relatively high.
When you take this all into account, the main requirements for choosing which sites should host a Satellite device vary from one installation to the next. For example, some customers, even though the available bandwidth with SITE 2 is high, might still want to have a device locally designated as a Satellite device. In this case, a workstation-class machine should be more than sufficient to manage the devices at that site.
The suggested placement of Satellite devices should be based on simple rules. Some examples of sites that are good candidates for Satellite devices are as follows:
Sites with more than 200 devices.
Sites that have high cost or limited access links between the MD and Primary Servers.
Sites where the bandwidth per device per hour is less than x. In the examples above, 5 MB was chosen because this is the average size of a patch.
Sites that have secure locations to store devices. Customers might not want to place dedicated Satellite devices in locations where they cannot be secured. In other words, you want to avoid a situation where a user turns off the Satellite device or physically removes it from the network.
Sites with limited or charged access to WAN Infastructure.
You should ensure that your network environment is well designed for ZENworks Configuration Management. You need to ensure the following:
DNS forward and reverse lookup is properly configured so that you can resolve servers by using their DNS names and IP addresses. VNC, for example, relies on the DNS infrastructure. For this reason, it is important that the DNS service is well designed and implemented. If it is not, the problem needs to be addressed during the design phase, properly documented, and resolved before deployment begins.
We recommend that you register all of your managed devices in DNS, which makes it easy to resolve by name. This is possible only if Dynamic DNS is in place and properly configured.
DHCP must be properly configured for imaging purposes, and your network team should work with you to ensure that you can image across multiple subnets if necessary.
PXE must be enabled on your workstations if you choose to leverage the automated imaging functionalities.
Time synchronization is an important factor for a stable ZENworks Configuration Management design. Configuration items and deployment tasks, such as bundles, inventory uploads and access to user sources, rely on time stamps to ensure secure access to the relevant data. If servers and devices have different times, this can cause a number of communication issues with the Management Zone.
We recommend that all devices have their time synchronized. This includes Primary Servers, the ZENworks Database, and managed devices.
For eDirectory customers, we recommend pointing the ZENworks Configuration Management Servers to eDirectory Time Sources via NTP. All clients usually use the same time source via the Novell Client, so the system is synchronized. For all customers, we recommend that a single source be used for synchronization.
The introduction of the new ZENworks Configuration Management architecture means discontinued support for the NetWare operating system for both the Primary Server and the Satellite devices.
Customers are encouraged to consider migrating to Open Enterprise Server (OES) Linux or to SUSE Linux Enterprise Server (SLES) 10, which are supported as hosted platforms for the ZENworks Configuration Management Server services. As part of the migration, consider the following options:
Migrating existing NetWare servers to OES Linux.
Complete migration away from the NetWare kernel
Virtualized on Xen on top of OES Linux
Running the ZENworks Configuration Management core Server services (Primary Server) on OES Linux
Running the ZENworks Configuration Management core Server services (Primary Server) on SLES 10
Running the ZENworks Configuration Management core Server services in a virtualized instance of either OES Linux, SLES 10, or Windows Server on top of OES Linux or SLES 10.
Refer to the design phase section of this guide for details on how to leverage an existing NetWare infrastructure for application deployment. Remember that by doing this you also require additional technologies and products, such as ZENworks Server Management.