COMP3122 Network Management Richard Henson March 2012

Week 6 – Installing & Auto- installing software n 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” n What happens at the server end is mostly [behind the scenes] –users rarely get involved… n Client-end matters are often “up-close- and-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 n 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 n 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 n Many ways to do this… –locally –across the network n Process can be automated –even boot-up can be done remotely via network card n Installation of software in sequence… –or copy disk image of “cloned” computer

Client Installation Methods: Sequence of Operations n 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 n 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 n 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 n 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 n 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 n CD-ROM drive on the server n Local machine accessible from the server n Either: –contents of CD-ROM copied across the network to local hard disk (slow) –software then installed from local machine (faster) n Or: –Software installed directly to local machine from network CD-ROM (slow)

Client Installation Methods: 4. USB across the network n Assumes previous copying of app(s) to USB: –memory stick then plugged into USB the server n Either: –USB data copied across the network to local hard disk (fast) –then software installed from local machine (fast) n Or: –software installed directly to local machine from network CD-ROM (fast)

Client Installation Methods: 5. Directly from Server Hard Disk across the network n Software all previously copied to server hard disk (CD-slow, USB-faster) n Then either: – data copied across the network to local hard disk (fast) –software then installed from local machine (fast) n Or: –Software installed directly to local machine from network server (fast)

Client Installation Methods: 6. To multiple clients simultaneously from server n Software all previously copied to server hard disk as before (CD-slow, USB- faster) –data copied simultaneously across the network to many local hard disks (slow) –apps then triggered to install “unattended” on local machine (fast)

Unattended Installations n 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 n 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 n “Batch file” written to answer set-up program all these questions automatically –accessible to all “hardware clone” clients from the server n 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 n 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” n All commands executed automatically, and very quickly, without user intervention

Creating the scripts for an unattended installation n 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 n 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) n Motherboards now have a program in the BIOS settings (PXE-BIOS) that can be activated remotely to start the boot-up process n 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 n 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… n Whichever system is used the operating system needs to be available from hard disk on a network server…

Remote booting an older BIOS n Old machines do not have motherboards that support the PXE remote boot environment n However, a tool is available with Windows servers that enables remote booting on a non- PXE 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 n 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… n 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 n Major occupier of network administrators time –The only more time-consuming tasks are installations and managing logons n 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 n 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) n The former is: –quicker and more flexible for the user –a potential pain for the system manager!

Assuming “fat” Client Installation… (still the norm) n Essential to make sure the application works as expected FOR THE GROUP(S) OF USERS WHO WILL BE ACCESSING IT! n May need alterations to: –application configuration –user permissions n Also essential to repeat this cycle for each application installed

Rolling out a completed client setup across the network n 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 n Or could use “disk imaging”

Disk “Imaging” or “Cloning” n The principle is a simple one: –keep a copy of the sector-by-sector contents of the client hard disk on the server n 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 n Only computers with identical hardware and applications will have identical disk images –even small hardware changes require different drivers, etc. n 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) n Good reason to buy client computers in bulk!

Achieving the disk (or partition) “image” n Software needs to: –scan and copy a hard disk sector –write that sector to a new location n Repeat until all sectors copied –very many sectors involved… –time consuming process n Same principle used in defragmenting files –but latter copied to the SAME partition

Using the Disk Image n 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) compliantassuming 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) n Popular for imaging over many years n 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!) n Image file saved as.ghs (if >2 Gb “spanned”) file

Remote Installation Tools for Managing Installations n 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 n 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 n 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 n Unattend.txt –script providing answers to setup questions n Setup Manager –tool that automatically generates unattend.txt files

Windows Application Installer Tool n 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) n 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 n 1. Strips the SID from the PC being imaged n 2. installs a miniature version of Windows Setup n 3. imaging software clones the "reference machine” n 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 n makes the imaging process totally “hands free”

SYSPREP (continued) n Target PCs must all use the same HAL, NTOSKRNL.EXE, and boot device n Several sysprep support files required: –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) n Setupmgr.exe used to automate the “mini-setup” process n Answer file must be named sysprep.inf n BOTH saved in the C:\SYSPREP folder n C:\SYSPREP folder removed as part of the installation process

Windows RIS (Remote Installation Service ) n 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 n Three requirements at the server end –not necessarily all on the same machine –should all be on the same subnet) n 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. DHCP server supplies IP address to client 2. RIS server provides boot file & PXE- boot environment for client 3. Client prompts for F12 to “network boot”

Advanced RIS n RIS equivalent for cloning Windows servers n No real excuse for not having a backup… –if an administrator is capable enough to manage users and clients… »server cloning certainly no more challenging!!!

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