Active Directory, the repository of information that underpins
Microsoft Windows 2000, is difficult to reconfigure once it has
been implemented, but the problem of getting it right first time is
being tackled through a product from UK company Xellirate, writes
Eric Doyle.
The tool, dubbed Directorysim allows virtual modelling of a
projected roll-out of Active Directory, taking into account
end-user profiles, distribution, server locations and
configurations.
John Earley, managing director of Xellirate, said, "Senior IT
managers in large enterprises have little choice but to migrate to
Windows 2000 Server and, by default, implement Active Directory. In
addition to being an entirely new application, Active Directory is
particularly daunting because it reaches every part of the network
and poor implementation will result in an intolerable hit on
service level expectations."
Earley said Directorysim can reduce some of the uncertainties that
are left even after using Microsoft's utilities. ADtest, he said,
is merely a traffic generator and reporting tool which effectively
tests individual server configurations but cannot predict the
effect across a network.
ADsizer is little more than a spreadsheet calculator that works out
minimum server capacities but does not take into account server
locations and topographies and gives no analysis of user response
times, he added.
Consultants have stressed the importance of meticulous planning
before implementing Active Directory. Directorysim offers support
to create an effective plan more rapidly. Assumptions made
regarding new servers to support the system can be validated before
investing in costly hardware using the product.
The simulation engine that helps create the virtual model is
generic and forms the basis for several other network and directory
performance planning products. Within Directorysim it is used to
help managers avoid the specific challenges that Active Directory
poses and avoid the possibilities of system failures.
Earley said it can also be used in existing Active Directory
environments to show the effect any changes in configuration or
additions to the network may have on performance.