Transcript presentation6

COMP3122
Network Management
Richard Henson
March 2012
Week 6 – Installing & Autoinstalling software
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Objectives
– Explain different methods for installing
system and application software on client
machines
– Explain how installation can occur without
user intervention
– Explain how a complete system can be
rapidly installed on a client machine to
minimise downtime
“Serving Users”
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What happens at the server end is
mostly [behind the scenes]
– users rarely get involved…
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Client-end matters are often “up-closeand-personal”
– client machines in the hands of users
– users not able to do their job because
something isn’t working as they would wish
can be difficult to deal with
Managing Clients
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One of the most important parts of the
job of a network manager…
– potentially more troublesome as the
network gets bigger and more diverse
Managing Clients
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Having “happy” users
involves getting three
things right at the
client-end:
– user and group
settings
– applications delivered
via the desktop
– desktop settings
Client Installation
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Many ways to do this…
– locally
– across the network
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Process can be automated
– even boot-up can be done remotely via
network card
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Installation of software in sequence…
– or copy disk image of “cloned” computer
Client Installation Methods:
Sequence of Operations
 Applications
run on operating
systems…
– makes sense to install the operating
system first
– some methods (e.g. disk “imaging”)
do both simultaneously
Client Installation Methods:
1. From Local CD-ROM
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Software issued by suppliers on CD-ROM or
DVD-ROM
– could just install operating systems and
applications to individual machines via CD-ROM
drive on the client machine
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Problem… TIME! CD-ROM slow
– modern systems software and applications are
EACH often large (> 500 Mb)
» long time to copy CD -> hard disk
– replicated many times to install all this on all
machines in a typical network
Client Installation Methods:
2. from local hard disk
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Convenient if operating system already
installed
– applications all copied “en bloc” from CD-ROM to
local hard disk (may need a large hard disk…)
– technician can get on with other tasks while the
apps installation files are copying
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Installation program then executed directly
from local hard disk
– rapid copying because no CD-ROM involved
– significantly faster than CD-ROM based
installation
Client Installation Methods:
3. CD-ROM across the network
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CD-ROM drive on the server
Local machine accessible from the server
Either:
– contents of CD-ROM copied across the network to
local hard disk (slow)
– software then installed from local machine (faster)
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Or:
– Software installed directly to local machine from
network CD-ROM (slow)
Client Installation Methods:
4. USB across the network
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Assumes previous copying of app(s) to USB:
– memory stick then plugged into USB the server
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Either:
– USB data copied across the network to local hard
disk (fast)
– then software installed from local machine (fast)
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Or:
– software installed directly to local machine from
network CD-ROM (fast)
Client Installation Methods:
5. Directly from Server Hard
Disk across the network
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Software all previously copied to server hard
disk (CD-slow, USB-faster)
Then either:
– data copied across the network to local hard disk
(fast)
– software then installed from local machine (fast)
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Or:
– Software installed directly to local machine from
network server (fast)
Client Installation Methods:
6. To multiple clients
simultaneously from server
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Software all previously copied to server
hard disk as before (CD-slow, USBfaster)
– data copied simultaneously across the
network to many local hard disks (slow)
– apps then triggered to install “unattended”
on local machine (fast)
Unattended Installations
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Whilst software is being installed on a
computer, the set-up program asks a series of
questions…
– means that the installation cannot be fully
automatic
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However, for a given hardware setup it is
possible to create and use a text file
containing appropriate answers to the set-up
program’s questions
– the set-up program processes these directly
– fully automated installations then occur…
Managing Unattended
Installations across the network
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“Batch file” written to answer set-up program
all these questions automatically
– accessible to all “hardware clone” clients from the
server
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With Windows 2000 etc., batch file saved as
UNATTEND.TXT
– to take account of the different hardware
specifications of client machines, a number of
“unattend” files need to be available on the server
“Batch” or “Script” files
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Just a series of commands for the
operating system e.g.
– Autoexec.bat (from MS-DOS)
– Win.ini (from Windows 3.1)
– Unix “shell scripts”
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All commands executed automatically,
and very quickly, without user
intervention
Creating the scripts for an
unattended installation
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At first sight, two alternatives:
– EITHER
» created manually, from knowledge of the setup
program, and the information it would request
» perhaps with the help of template files…
– OR
» created automatically with software as a result of
checking the system configuration of a machine that
has already been set up
Creating a system for unattended
installations on clients
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A very clever system could do it all…
– check any client computer to be used on the
network
» make note of the drivers, settings, etc.
–
–
–
–
use this information to generate a script
store the script on a network server
allow access to the script across the network
execute the script whenever a similar installation
is to occur on a similar type of machine
Starting Computers Remotely
(Remote boot motherboard)
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Motherboards now have a program in the
BIOS settings (PXE-BIOS) that can be
activated remotely to start the boot-up
process
Requires client to be already switched on and
connected via network to server…
– very useful, and greatly labour saving!
– can be used to activate a client machine at some
distance from the server remotely so that software
can be installed
Remote Installation “from
scratch” on a new client
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Client with PXE-BIOS needs to be able to
boot up…
– by accessing, downloading, and executing an
operating system boot program remotely across
the network
– which will then trigger the operating system
remote install…
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Whichever system is used the operating
system needs to be available from hard disk
on a network server…
Remote booting an older BIOS
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Old machines do not have motherboards that
support the PXE remote boot environment
However, a tool is available with Windows
servers that enables remote booting on a nonPXE motherboard
– such a useful thing to be able to do!
– means that any clients, no matter what the age of
the motherboard, can always be remotely
configured
Upgrades to Operating
Systems and Applications
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Upgrading an operating system across a
network is a major undertaking
– carefully planning!
– all data needs to be backed up
– applications may need to be reinstalled
» sometimes quicker to start again from scratch than go through
the lengthy upgrade process…
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Upgrading an application across a network is
usually a simpler process
– still benefits greatly from automation
Setting up Applications so users
can use them appropriately
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Major occupier of network administrators time
– The only more time-consuming tasks are
installations and managing logons
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Need to ensure:
– that the required applications ARE available
– that users have an appropriate desktop to provide
access to them
– that users have sufficient rights to use applications
in the way they need to use them to do their job,
etc.
Ways to make Applications
available for Users
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Available:
– as fat/thick/rich client:
» user accesses application from local hard disk
– as thin client:
» user downloads a copy of the application from the server
– via Virtualisation (a server-based virtual machine)
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The former is:
– quicker and more flexible for the user
– a potential pain for the system manager!
Assuming “fat” Client
Installation… (still the norm)
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Essential to make sure the application works
as expected FOR THE GROUP(S) OF USERS
WHO WILL BE ACCESSING IT!
May need alterations to:
– application configuration
– user permissions
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Also essential to repeat this cycle for each
application installed
Rolling out a completed client
setup across the network
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Could repeat installation processes for
each application
– create and use unattend scripts to allow
installation to proceed automatically
– copy each application individually to each
client machine
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Or could use “disk imaging”
Disk “Imaging” or “Cloning”
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The principle is a simple one:
– keep a copy of the sector-by-sector contents of the
client hard disk on the server
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Specialist software is required to achieve this
– separate image created for each type of client
computer on the network
» different hardware requires different drivers
– each image needs to be stored on the server
Disk “imaging” – continued
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Only computers with identical hardware and
applications will have identical disk images
– even small hardware changes require different
drivers, etc.
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A unique image must be created for each
batch of computers used
– each image will require a large amount of space
on the server(s)
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Good reason to buy client computers in bulk!
Achieving the disk
(or partition) “image”
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Software needs to:
– scan and copy a hard disk sector
– write that sector to a new location
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Repeat until all sectors copied
– very many sectors involved…
– time consuming process
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Same principle used in defragmenting files
– but latter copied to the SAME partition
Using the Disk Image
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Copying the data back from server to client
needs careful management:
1. The client machine needs to have access to an
operating system in order to boot up
•
assuming the BIOS is PXE (Pre-boot eXecution
Environment) compliant
2. Once the client is “active”, it can support
copying the image across the network
3. The client machine, with a full installation of
operating system and applications, should
reboot, and in theory would be “ready to roll”
Example of a “clean installation”
tool (Norton Ghost)
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Popular for imaging over many years
Sector-by-sector copying only
– this would create identical clients with same IDs
– feature allows a unique SID to be added for each
Windows client
– but not for applications… (problem!)
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Image file saved as .ghs (if >2 Gb “spanned”)
file
Remote Installation Tools for
Managing Installations
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A useful tool needs to (unattended installations):
– generate unattend scripts for operating system and
application setups
– manage all aspects of each unattended installation
including the allocation of unique IDs
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For imaged installations…
– create an image (or clone) of a client (or server) hard
disks & allow it to be accessible via server
– manage the restoration of data by copying the image
from a server to a corrupted, but undamaged, hard
disk, and resolve ID conflicts
UNATTEND tools with
Windows-series networks
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WINNT (or WINNT32): Setup program itself
– Used with switches e.g.
» /s path to allow installation from a remote source
» /u path for an unattend script
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Unattend.txt
– script providing answers to setup questions
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Setup Manager
– tool that automatically generates unattend.txt files
Windows Application
Installer Tool
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MSIEXEC.EXE
– uses windows installer (.msi) files which
provide installation information as a script
– executes commands to:
» copy files to target machine
» make changes to registry
» create desktop shortcuts
Windows IMAGING (SYSPREP)
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Sysprep
– tool specifically for organizations that use
disk cloning for mass deployments
– will clone a particular machine once an
image of an identical machine has been
created
– further (third party) software is needed to
create the image from another client
» takes that sector-by-sector copy of the disk
SYSPREP, continued
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1. Strips the SID from the PC being imaged
2. installs a miniature version of Windows Setup
3. imaging software clones the "reference
machine”
4. new PC pxe-booted using the new image:
– mini-setup runs:
» specifies network info, languages and locales, display
settings…
» question responses can be scripted by using a answer file,
sysprep.inf
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makes the imaging process totally “hands free”
SYSPREP (continued)
Target PCs must all use the same HAL,
NTOSKRNL.EXE, and boot device
 Several sysprep support files required:
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– sysprep.exe, setupcl.exe, others
– must be contained in the C:\SYSPREP
folder of the image
– can be copied from the Deploy folder on
the Windows 2000 installation CD
SYSPREP (continued)
Setupmgr.exe used to automate the
“mini-setup” process
 Answer file must be named sysprep.inf
 BOTH saved in the C:\SYSPREP folder
 C:\SYSPREP folder removed as part of
the installation process
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Windows RIS (Remote
Installation Service)
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Manages the complete process cleanly
installing an operating system and
applications to a client
– not “sector-by-sector” cloning
– can cope with different types of client using
different UNATTEND files
– uses PXE to reboot the client and connect
it to the network after disk image created
More about RIS
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Three requirements at the server end
– not necessarily all on the same machine
– should all be on the same subnet)
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These are
– active RIS on a server (with active directory) to
manage the process
– active DHCP to deliver the IP address for the
client that is to be remote booted
– installation files (on a partition separate from RIS)
to download and install an operating system on
the new client
Sequence of RIS processes
1.
2.
3.
DHCP server supplies IP address to
client
RIS server provides boot file & PXEboot environment for client
Client prompts for F12 to “network
boot”
Advanced RIS
RIS equivalent for cloning Windows
servers
 No real excuse for not having a
backup…
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– if an administrator is capable enough to
manage users and clients…
» server cloning certainly no more challenging!!!
Thanks for Listening
