With MSI, however, the process is much simpler. You just need to answer
several questions to create a setup package and then save it as an MSI file. The
setup file format will most likely be the same in all vendors' applications
because Microsoft created a unified table-driven method for answering setup
questions. Microsoft developed this method with other software developers, so
most new applications will be MSI compliant.
Why are independent software vendors supporting MSI? Because MSI supports
ZAW, and a lot of big clients want ZAW. In addition, vendors' applications won't
qualify for the Designed for Windows logo without MSI support.
Besides using MSI for self-healing applications, you can use MSI for
installing and removing programs. Suppose you want to distribute a new word
processor, WordBlaster, to your users, but you want to spend as little time and
shoe leather as possible. With MSI, all you do is assign the application to an
NT group, such as Everyone.
What does assign mean? Under NT 5.0, you can centrally modify the Start
Programs menus of all your users to include particular applications, even if
those applications aren't on those users' systems. (Currently, you can centrally
control people's Start Programs menus with system policies. Just like many other
ZAW features, the assign feature is just an enhancement of existing
technologies.) When users log on, they'll see a menu option for WordBlaster even
though you have not installed WordBlaster on their systems. When they try to
start WordBlaster, the operating system realizes that WordBlaster isn't properly
installed and the self-healing application process kicks in.
At this point, you might be wondering about what permissions you'll have
to give users--after all, users must have a fair amount of power over their
workstations to install applications, right? Not quite, because the user doesn't
install the software, MSI does. But don't be surprised if a whole new class of
NT security holes develops once hackers figure out how to build a command prompt
that runs in MSI space.
Besides assigning an application, you can get an application into the ZAW
world in two other ways. You can make an application generally available by
publishing it in the Active Directory (AD). The application doesn't go into the
AD. Rather, the AD contains the instructions about where to find it. When users
start the Install New Programs wizard in the Control Panel, they'll see that
list of programs. Another way to make an application generally available is
through the Class Store. For information on how the Class Store works, see my
article "NT 5.0 Gets Better and Better--Mostly," page 124.
Removing a program is as simple as installing one. Suppose you want to
discard a current application of Word because you want new settings. But if you
remove and then reinstall an application, it remembers all your settings from
the first installation. Clearly, the removal process doesn't include cleaning
out the Registry settings relevant to Word.
With MSI, this situation changes. When removing a program, MSI will delete
all files relevant to an application and all Registry entries.
MSI and IntelliMirror work well together. Suppose Sally, a WordBlaster
user, tries to run WordBlaster, but it's not yet on her machine. NT 5.0 uses the
MSI package you prepared to install WordBlaster quickly and silently. You set up
WordBlaster with a network installation option, so no files go on Sally's
machine. Instead, they're all on her space on the network, so the data can roam
with her more easily. Despite working on the network, WordBlaster runs quickly
for Sally because her workstation is running from the program files in the local
IntelliMirror cache. Furthermore, if the server's down, Sally can still get work
done because her workstation is using the local cache. In the meantime, you can
update and install patches on WordBlaster more easily because the application is
on the server.
SIS: A Smart Idea
If 2000 users all install WordBlaster and it's a network install, will you
end up with 2000 copies of WordBlaster on the server? Don't run to your
stockbroker to buy Seagate stock just yet. ZAW avoids having 2000 copies with
the Server Intelligent Storage (SIS) server-side program. With SIS, you
designate a section of a server's storage as an SIS area. When a user saves a
file to that server, the server checks the file against the other files in the
SIS area. If that new file is identical to an existing file, SIS doesn't save a
second copy of the file. Rather, SIS just stores a directory entry for that
file.
SIS sounds like a very cool technology, but I wonder about how CPU
intensive it'll be. My guess is that adjusting SIS sizes will be one of the
great tuning pastimes of NT 5.0 Server administrators.
What does SIS mean for laptops? Suppose you are a PowerPoint user and you
set up PowerPoint to run from the network. What happens when you take your
PowerPoint on the road?
In theory, SIS will work effectively because when you run PowerPoint on the
network, IntelliMirror copies the PowerPoint program files into the local
IntelliMirror cache. So when you're on the road, the program files will be
available. In reality, however, you can run into trouble two ways.
If you've never used PowerPoint's Rehearse Timings feature before, you
might get into trouble the first time you use PowerPoint on the road. PowerPoint
will request the file rehearse.dll--and it will not be in the cache because your
system never requested the file before. Your laptop will respond by trying to
reinstall (i.e., self-heal) PowerPoint because you originally installed the
application from the network. From this point, the problems will escalate.
Another way in which you might get into trouble is if you used numerous
network files before leaving the office, causing IntelliMirror to flush the
PowerPoint files from the cache. (If you use more files from the server than you
have hard disk space for, IntelliMirror determines which files are important. It
keeps the important files and lets the others expire out of the cache.)
You can avoid both problems by pinning PowerPoint in the cache. If
you know that you're going to need a particular application, you pin it, which
tells IntelliMirror to collect all the files that the application might need and
keep those files in the cache. In other words, pinning a file tells
IntelliMirror not to let that particular file expire out of the cache.
BIOS: The Pièce de Résistance
With ZAW, you can perform clever client-side caching (IntelliMirror), easily
install and remove applications (MSI), and minimize the amount of space used on
the server (SIS), all from a central location. Could it get any better? What if
you could install an entire operating system from a central location?
Microsoft envisions that ZAW will be able to provide this capability. Consider
the following scenario:
It's 8:00 a.m. You come to work and turn on your computer, Sparky. A funny
noise comes from the hard disk, and smoke comes out the back. A quick inspection
of the melted SIMMs and cratered CPU inside leads you to believe that Sparky's
computing days are over. You were planning to get some work done, but
installing and configuring NT Workstation, the Office Suite, and assorted other
applications will now occupy most of your day.
With ZAW, the day will proceed differently. After your quick inspection of
Sparky, you tell your network administrator about the casualty. You then say
good-bye to Sparky and search for a computer that no one is using. You find a
vacant computer and log on. Because all your applications are ZAW compliant and
you keep your data in My Documents, all of your applications and data are
available. MSI performs a couple of silent installs, and you are back in
business in a half-hour.
Meanwhile, the network administrator takes a new computer out of the box
and assigns it to you. She tells the network that you have a new computer,
identifying it to the network. She then brings this computer to your office,
plugs it into Sparky's old Ethernet jack, and turns it on.
The new computer is either a NetPC or a regular PC that follows the PC98
specification, so it has a smarter BIOS than most PCs have. The PC BIOS includes
support for network cards, the Dynamic Host Configuration Protocol (DHCP), and
the Trivial File Transfer Protocol (TFTP). When the PC powers up, the BIOS knows
enough about the network card to use it to get the PC an IP address via the
DHCP. With the other DHCP information, the new computer gets the address of an
install server. The new computer then sends a request for configuration
to the install server. The install server checks a database to determine which
operating and system applications this computer needs and assembles the
necessary files. The install server then uses TFTP to transfer the files to the
new PC. In no time, the new computer works as well as old Sparky did, maybe even
better.
How did the install server know that this new computer was your computer?
PCs with the improved BIOS have a globally unique ID (GUID), which an
administrator can use to identify that PC to the install server. With GUID, you
can configure systems on a user-specific basis. For example, instead of
specifying that a particular machine gets Windows 98 (Win98), you
specify that a particular user gets Win98. When that user logs on, the
system installs Win98.
In fact, each time users log on to a system, that system will do a
fresh install of their operating system and applications. A fresh install might
sound like a lot of work, but 999 out of 1000 of these installations will take
almost no time because all the files will already be in the local IntelliMirror
cache.
Fortunately, you don't need new PCs to run the improved BIOS. You just need
a bootstrap floppy to get the process rolling the first time.
Good Things Come to Those Who Wait
Computer support specialists have waited a long time for an initiative such
as ZAW. But ZAW will be worth the wait because it includes some terrific and
exciting capabilities. Central control of machine and application installation
and configuration is just plain wonderful.
But central control and all of ZAW's other features will work only if the
applications vendors go along with ZAW. More important, ZAW will work only with
one operating system. For ZAW to work, you must be running NT 5.0 on all
your desktops.